"There will be a reckoning to come," Harbaugh said. "I worry about Frank. I like Frank, and he's a 49er. I hope Frank comes back."
Gore is in the final year of his deal. He has been deemed healthy by his agent, Drew Rosenhaus, who didn't immediately respond to phone messages or email inquiries.
Gore went down with a season-ending fractured hip during a Monday night game at Arizona on Nov. 29. Gore, who avoided surgery on the hip, ran for 853 yards and three touchdowns in his sixth NFL season and caught 46 passes for 452 yards and two touchdowns.
Shortly after re-signing with the team on a one-year deal Friday, quarterback Alex Smith said he has spoken to Gore often this summer and likely will make contact with him again soon.
"It's part of the business. The contract side is something that we deal with," Smith said. "You hope for it never to interrupt the football side, but sometimes it does."
Gore can be fined $30,000 for each day of camp missed under the new NFL labor agreement. Of course, he could make that up and more if his wish is granted.
The 49ers have been reluctant to extend Gore's contract because they didn't have the opportunity to even see him on the field during the lockout. Gore also has a long history of injuries, and at age 28, he's entering the part of his career where most running backs usually begin to break down.
"As far as Frank, I wish he could get in here, but it's not under my control," tight end Vernon Davis said. "I know he's trying to get some things done. That's all I can say about that."
For as many times as Gore has been injured, he has returned even stronger.
The former University of Miami standout tore a ligament in his left knee that forced him to miss the 2002 season for the Hurricanes, and he previously had a similar injury in his right knee. The knee problems were the biggest reasons Gore slipped to San Francisco in the third round of the 2005 draft, and he has proved to be a major steal.
Gore's 24 100-yard rushing games are the most in 49ers history. He is 2,275 yards shy of breaking the franchise mark of 8,689 yards set by the late Hall of Famer Joe "The Jet" Perry.
"The great thing about Frank is he's going to have no problem picking up stuff," Smith said. "He's one of the smartest football players I've ever been around. You'd love to have him here obviously. But I think if there was somebody that could really make the most of a short number of practices, it's him."
Copyright 2011 by The Associated Press