Weidman has had 22 or 23 surgeries, that's the reason for his decline.

[Rum]

I know a lot of fans blame USADA, but that's only because he was undefeated pre-USADA and has gone 1-5 since ...

 

[dracul]

USADA ERA

 

[lostdog000]

and hes 35, most fighters peak at 30

 

[Privateeye0]

He still managed to come back and beat Bisping: