"It's something that's part of the business," coach Kyle Shanahan said Tuesday about Aiyuk's absence. "Anytime it's part of the business part, you try to respect it. Stay out of as much as possible and look forward to the days when you can just focus on football."
Bosa skipped last year's voluntary workouts as he sought a new contract, and spent most of the 2021 and 2022 offseasons back home in Florida, after missing the 2021 offseason rehabilitating a knee injury and the 2020 offseason because of the pandemic.
Bosa said Shanahan called him earlier in the offseason to ask him to come to the voluntary practices this year after the Niners added several new linemen in free agency and hired a new coordinator in Nick Sorensen.
"I think it's just good to get around the new guys," Bosa said. "We have a lot of new faces this year. Just kind of helping the new guys out. I don't think there's really been much of a normal offseason for me in terms of we had COVID, we had my injury and the contract situation. It's kind of a new year. I want to be around. It's good to be around."
Aiyuk is in a similar spot to where Bosa was last year when he was looking for a new contract that finally came following a lengthy holdout that ended just a few days before the start of the regular season.
Aiyuk is set to play on the fifth-year option worth about $14.1 million this season and wants a long-term contract that would pay him significantly more money based on his production so far in his career. Several of the top receivers have contracts in the $25 million a year range.
Aiyuk was a key part of San Francisco's offense last season as he formed a great connection with quarterback Brock Purdy. Aiyuk had 75 catches and a career-high 1,375 yards last season with seven touchdowns as he earned second-team All-Pro honors.
Aiyuk has 269 catches for 3,931 yards and 25 TDs in four seasons since being drafted 25th overall in 2020, but has taken off since Purdy became quarterback.
"He's a playmaker," Purdy said. "I love throwing to him. Love BA as a person. It's definitely important. But it's out of my control. For me, I'm showing up every day trying to get better with the new guys and the guys that are here."
Aiyuk wasn't the only notable absence with All-Pro running back Christian McCaffrey, All-Pro left tackle Trent Williams and receiver Jauan Jennings among those not taking part in the practices this week. New defensive tackle Maliek Collins is also not on hand but does plan to join the team after his kids finish their school year.
Williams typically works out on his own in Texas during this portion of the offseason and Jennings can't practice until he signs his restricted free agent tender. Shanahan gave no reason for why McCaffrey did not attend.
Several other key players aren't taking part in on-field work as they recover from injuries or surgeries, including tight end George Kittle, cornerback Charvarius Ward, linebacker Dre Greenlaw, safety Talanoa Hufanga, center Jake Brendel and defensive end Drake Jackson.