Hayden Panettiere & Scotty McKnight Split -- IT'S OVAH!!!!!

Hayden Panettiere and her football player boyfriend Scotty McKnight are officially broken up ... this according to sources close to the couple.

Sources tell us ... the two broke up a couple of weeks ago ... but it wasn't a nasty breakup. We're told the two are still "really good friends."

One source tells us, "They will probably be back together sometime down the road."

Scotty -- who played for the NY Jets -- is the 2nd pro athlete Hayden has dated -- she was with pro boxer Wladimir Klitschko for a year and a half starting in late 2010.

Meanwhile, Hayden's already showing signs of post-breakup hotness ... as demonstrated below in a screen grab from her show "Nashville."