SANTA CLARA — Nick Bosa recently revealed a lesser-known secret: The 49ers star is superstitious. During pregame warmups, the All-Pro pass rusher always wears the same sleeveless undershirt and black shorts. While that combination isn't unusual, what's immediately noticeable is the shirt's tattered and ragged condition. Of course, the 49ers would supply Bosa with new gear if he wanted it, but he told NBC Sports Bay Area that he doesn't want to replace the shirt he's worn in every game since his debut in 2019. “When you play football, you can't help but be superstitious,” Bosa said. “I try not to be, but you'll see me knocking on wood every 10 seconds, and that's just part of this game where everything is so uncertain that you get superstitious.” The shirt, which Bosa originally cut the sleeves off of, has a jagged hem that has seen better days after being worn in 68 regular-season games and another 12 postseason games. The undershirt is also nowhere near its original white color after surviving 3,253 defensive snaps and 44 on special teams. “That's a lot of stinking football players,” Bosa said, laughing. Bosa's practice undershirt, …