SANTA CLARA — Patrick Willis hollered at pal NaVorro Bowman a few days back to keep him in the mix, even if the star linebacker was a bystander as his teammates endured their Day 1 conditioning tests.
Willis is so accustomed to running through drills right alongside Bowman that 49ers training camp seems a bit strange without his position mate and close friend.
Bowman is expected to miss at least half the season as he recovers from a devastating left knee injury sustained in the NFC championship game loss to the rival Seahawks.
"We were out there doing a conditioning test and I looked over and he was watching us do our conditioning test and I wanted to just yell at him, 'Bo, what's up, man?'" Willis said. "I don't want to put more on him than what he already has on his shoulders already. I know that he wants to be out there more than anything."
There are a handful of candidates in the mix to fill that huge void left by No. 53.
"I don't see it as daunting at all," linebacker Michael Wilhoite said Friday. "I see it as a great opportunity for somebody else to step up and make a name for themselves. ... You have to embrace the fact we're not replacing Joe Schmo. We're replacing the best. So that means you have to be the best."
Bowman tore the anterior cruciate and medial collateral ligaments and underwent surgery, and the 49ers must try to make up for the vacancy on one of the NFL's most vaunted defenses.
"I'm doing great," Bowman said with a smile as he entered Levi's Stadium.
It helps to have Willis and everybody else supporting him every step.
"I want him to take his time. Most of all I want to make sure when he comes back that he's ready to go and he doesn't have any setbacks. He's a great athlete and he still has a lot of football ahead," Willis said, noting his unit will be "working as we do every year to try to be the best linebacking corps there is in the National Football League."