Nick Swisher Bummed Over Christian Yelich's Injury, Brewers Might Be Done

Nick Swisher is heartbroken Christian Yelich won't return to the diamond this season after hurting his knee ... and he tells TMZ Sports he thinks the Brewers might be done after the devastating injury.

"I don't know, man," Swisher says. "That's a big hurdle to get over at this point in time."

Yelich -- arguably the front-runner for the National League's MVP award -- fouled a ball off his right knee Tuesday night ... and after the game, the Brewers said he'd be done for the season with a broken kneecap.

When we got Swisher out in NYC on Wednesday ... he told us things are looking grim for the Brew Crew's playoff chances now with their superstar out of the lineup.

But, Nick ain't completely slamming the door on Milwaukee's chances to make the postseason ... telling us, "At the end of the day, man, it's September baseball."

"Anytime you're playing good baseball in September, you feel pretty good about that."

The Brewers are just ONE GAME out of the second Wild Card spot in the NL ... and they are getting stars Mike Moustakas and Keston Hiura back this week -- so maybe there is a chance!!!