Veteran tackle Colton McKivitz ready for a fight during 49ers contract year

SANTA CLARA —It is common for offensive and defensive linemen to engage in one-on-one pass-rush battles on back-to-back snaps during training camp.But what Colton McKivitz and Nick Bosa did organically at the outset of 49ers practice Tuesday was unique.Bosa, a five-time Pro Bowl player, got the upper hand against McKivitz on their first head-to-head matchup with a spin move that put McKivitz on the ground.McKivitz was the winner of the next rep just moments later when Bosa was off-balance at the snap of the ball and could not recover.Apparently not pleased with the quality of that performance, Bosa indicated he wanted another chance against McKivitz.The third time showcased a competitive tussle in which McKivitz grappled with Bosa to the point it was difficult to assign a winner.That sequence summed up what McKivitz recently revealed to NBC Sports Bay Area about his mindset for the season.“A key word that I’m using this year is, ‘Fight,’” McKivitz said. “I do a lot better when things are kind of hectic and in chaos and when I’m fighting for something. I’m...