It looks like an engagement ring ... she's flaunting it like an engagement ring ... but the rock on Erin Andrews' finger is NOT an engagement ring.

Andrews has been dating L.A. Kings superstar Jarret Stoll for a while ... after she posted a pic with that huge diamond before last night's "Dancing with the Stars" premiere, there was buzz that he finally popped the question.

Turns out ... the ring wasn't from Stoll -- it was from wardrobe ... specifically so Erin would look "blinged out" for the big show.

But the ring was no cheap prop -- according to E!, it was a special asscher-cut diamond ring that weighed in at 2.01 carats with 22 baguette diamonds and 88 other microset diamonds.

Michael Sam blew the judges away last night ... at least his ass did ... because the wannabe NFL star's booty was the talk of the ballroom on last night's "Dancing with the Stars."

The dancing was fine. His footwork was sloppy ... but after Sam cut a rug to "Uptown Funk," judges Bruno and Len couldn't stop talking about the junk in Sam's trunk.

Bruno -- "That butt was a work of art. Michelangelo's 'David' has nothing on you."

Len -- "You could win 'Rear of the Year' and I could win 'Ass of the Past.'

With Season 20 of "DWTS" upon us, get swept off your feet with the 18 sexiest shirtless photos Val's teased on social media!

If this is how Carl's Jr. babe Charlotte McKinney plans to rehearse for her upcoming gig on "Dancing With the Stars" -- there's at least a chance we might be interested in that show again.

Hint for the 'DWTS' wardrobe department -- save the bikinis for Charlotte, and keep them away from Redfoo ... at all costs.

Of course, it's easier (and hotter) to just watch her burger spot instead.

"Dancing With The Stars" pro Karina Smirnoff changes fiances as often as she changes dance partners -- partly because dancers lead sexually charged lives ... this according to her latest ex.

Sources close to Jason Adelman -- who announced he and Karina were engaged in January -- say he called things off because she has "different family values." We're told he's not accusing her of cheating, but he was uncomfortable with the way she acted around other men ... especially dancers.

It's not like this was any long term engagement -- he just popped the question in January ... after they reconnected at a holiday party in December. As for his belief that dancers are all horned up people looking to bang -- a rep for Karina says that is "disrespectful and insulting to the entire dance community."

Our Adelman sources add that he feels Karina's track record speaks for itself ... she's been engaged twice before -- to fellow dancer Maksim Chmerkovskiy and MLB pitcher Brad Penny -- but never made it down the aisle. So much for the third time.

Karina's rep also says this is "nothing less than an attempted smear campaign from a malicious person."

For what it's worth ... we're told Karina returned the ring.

With just a couple of weeks until the NFL's veteran's combine, Michael Sam spent his Friday focusing on his footwork ... for "Dancing with the Stars!"

Sam left the DWTS rehearsal studios clutching a pair of ballroom dancing shoes ... and got into a waiting car with his boyfriend Vito.

"Dancing" premieres on March 16. The NFL veteran's combine is March 22.

Question is ... can Sam have his cake and eat it too?

Michael Sam's decision to join "Dancing with the Stars" does NOT mean he's throwing in the towel on his NFL career ... so says his friend Jason Collins who says he can't wait to watch the guy kill it in the ballroom.

Sam's been taking heat from critics who say the decision to join "DWTS" shows he's more concerned about being a celebrity than playing in the NFL.

But Collins -- who famously came out as the NBA's first openly gay player in 2013 -- says the haters are wrong ... and he's got proof to back up his argument.

Michael Sam is adamant ... his decision to join "Dancing with the Stars" does NOT mean he's giving up his NFL dreams ... saying, "Football remains my unquestioned number 1 priority."

TMZ Sports broke the story ... Sam signed on to join Season 20 ... which begins next month.

Some people have said the move is proof that Sam is throwing in the towel on his football career and wants to focus on exploiting his off-the-field fame.

But moments ago, Sam fired back at the critics ... saying, "Football remains my unquestioned number 1 priority, however, while I continue to train and stay ready, I am ecstatic to participate in a fun, athletic competition like so many players before me have done."

"Filming this off-season is very flexible and allows me to be part of the veterans combine 3/22 if accepted or any other workouts."

Michael Sam will be competing in March, not on the football field, but on the "Dancing with the Stars" hardwood ... TMZ Sports has learned.

Michael -- the first openly gay player drafted in the NFL -- will be part of Season 20, which fires up next month.

Here's the problem. Sam -- who insinuated he was cut from the NFL because he is gay -- has vowed to get back in the league and said he'd take part in the first-ever veteran's combine on March 22.

But Sam needs to prove he has what it takes, and we're thinkin' some of the owners might question his commitment if he's focusing on the rumba rather than rumbling.

Rob Gronkowski tells TMZ Sports he's definitely thinking about doing "Dancing with the Stars" one day ... but says he's worried that formal training will RUIN his trademark skills.

Gronk was out in NYC this weekend ... where he broke SEVERAL pieces of big news, including:

-- Did he nail that hot local reporter on Valentine's Day?
-- He's been training teammate Chandler Jones to fight his brother Jon "Bones" Jones
-- He NEVER wants to leave the New England Patriots.

Oh, he also notices our photog is wearing a Miami Dolphins hat ... SO HE SPIKES THE HELL OUT OF IT!!!

Check out the clip -- amazingness.

Derek Hough isn't ready to admit he's banging Kate Hudson -- but he's definitely not denying it either.

The "Dancing with The Stars" pro was in Boca Raton Thursday -- at a Tony Robbins seminar of all things -- when a photog popped the question about rumors he and newly single Kate are hooking up ... and his response is a little weird.

Hough and Huds were reportedly making out at an L.A. hot spot last Friday night -- he left out the front door, and she was spotted sneaking out the back -- sans engagement ring.

So, Derek ... if you're NOT with her ... why not just say so? Just sayin'.

Before Jonathan Bennett hit the "Dancing With the Stars" ballroom, he got turnt up with some interpretive dance ... a Bette Midler classic ... and one of the wildest, most painful staircase falls we've ever seen!

So much for the wind beneath his wings.

Jonathan Bennett's "Dancing With the Stars" appearance almost never happened ... because he suffered a humongous fall as he jokingly tried to prep for the show ... and it was all caught on tape.

So here's the deal ... the "Mean Girls" star shot this video a few months back, but kept it hidden until "DWTS" finished its run (congrats, Alfonso).

In the video, he and a few friends attempt an "interpretive dance" ... but Bennett tried a move on the railing of a staircase that ended ... well, you gotta see it. He ended up with 2 broken ribs and his arm in a sling for 2 months.

The best part -- they were dancing to "Wind Beneath My Wings."

Seeing as he was the one who allowed the video to be posted ... Bennett's ego escaped unscathed.

Tom Bergeron hit a little too close to home Monday night on "Dancing With the Stars" ... when he made a stalking joke about Erin Andrews ... who very famously dealt with a stalker of her own.

Andrews was debriefing Alfonso Ribeiro when she began gushing over Will Smith ... who went on a social media campaign supporting his former "Fresh Prince of Bel Air" co-star.

After Andrews repeatedly invited Will to show up to a taping, Bergeron followed it up by saying Will could do worse than having Erin as a stalker ... insinuating it's ok for hot chicks to stalk guys.

Janel Parrish just had her chances of winning the Mirrorball Trophy derailed ... at least that's the way it looks after she suffered a gnarly injury during rehearsal.

TMZ just got this video of the "Pretty Little Liars" star and Val Chmerkovskiy practicing lifts. Something bad clearly happened because you see her dissolve into tears as she hobbles to a room where doctors examine her.

It looks like she suffered a broken or compressed rib.

She hasn't been counted out, but it doesn't look good. The finals are tonight.

Janel Parrish is pulling double duty on "Pretty Little Liars" AND "Dancing with the Stars" -- and TMZ has learned she's spread herself so thin, she's alienated castmates on both shows.

DWTS sources tell us ... Janel's pro dance partner, Val Chmerkovskiy is freaking out ... because she's missed two days of critical dance rehearsals due to long days of filming on PLL.

We're told ... Val believes he and Janel have a real shot at winning the trophy -- the finals are Monday and Tuesday -- but thinks her PLL schedule is sabotaging their chances.

As for Janel's "Pretty Little Liars" co-stars ... we're told Lucy Hale and others in the cast have been conspicuously absent from the DWTS set the entire season ... and have given her little to no support -- even when she danced to the PLL theme song.