After tearing his ACL on the second day of training camp last year, TE Nate Byham was forced to spend the season rehabbing for a chance to compete for a roster spot this year. Regarded as an excellent blocker, Byham has found himself in competition for the third TE spot behind Vernon Davis and Delanie Walker. 

“[Rehabbing] was a rough process, but I fought through it and the knee feels good,” Byham said. “I feel it when I wake up, but that’s normal. Plus, we’re in camp so we’re going to be sore regardless. The main thing is that it doesn’t limit me on the field.”

The obvious competition for Byham is Konrad Reuland, who spent last season on the practice squad, but it’s not quite that simple. DL Demarcus Dobbs also factors into the equation as a potential two-way player. If Dobbs can prove he’s effective as a blocker in the team’s two- and three-TE packages, Byham’s value decreases.

A sixth-round pick in the 2010 draft, Byham had five catches for 27 yards in his rookie season.

Justin Smith sits out: DL Justin Smith watched Thursday’s practice from the sideline, but it was believed to be a courtesy off day for the veteran.

Crabtree still out: There is no timetable for the return of WR Michael Crabtree, who missed practice for the fifth-straight day with an apparent minor calf injury. Part of his rehab process included a series of sprints.

INTs galore: Chalk up Thursday’s practice as a win for the defense. All four of the team’s QBs threw INTs in red zone drills. One of the defensive highlights of the day was an INT from S Michael Thomas on a tipped ball.

Blitz pickups emphasized: The blitz pickup portion of practice was the most physical drill of the day. Anthony Dixon, who is auditioning at FB, stood out, and TE Konrad Reuland struggled to stay in front of quicker OLBs.

Greg Roman ... air traffic controller? The NFL has introduced improved headsets this year, which offensive coordinator Greg Roman said has made relaying plays much easier. Roman wasn’t a fan of the old models. “There was one time when I was doing it and it happened to be on the same frequency as an airline in a certain city and it was a critical situation in the game and all you hear is Southwest pilots talking,” Roman said.

Follow 49ers reporter Kyle Bonagura on Twitter: @CBSSportsNFLSF and @KyleBonagura.