Editor's note: Training camp is underway. For all the latest news from Santa Clara, check out our 49ers training camp page.
Practice summary: A.J. Jenkins had a strong bounce-back practice with three nice receptions just one day after the 49ers' top pick of 2012 was the only wideout held without a catch.
But the most unique sight on the practice field Tuesday was a scuffle matching two safeties who are competing for practice reps, playing time and, perhaps, a roster spot.
And the melee featured the coach Jim Harbaugh's swan dive onto the pile to try to break it up.
Veteran C.J. Spillman and Michael Thomas got into an argument, and Spillman took a swing at Thomas during the non-padded practice. The two players went to the ground. Receiver Ricardo Lockette was among the first on the scene to try to separate them.
The physical confrontation was the result of a dispute over practice reps, a source told CSNBayArea.com.
Then, Harbaugh, who does not condone practice-field scuffles, dove into the melee in an attempt to restore order. When the two players were separated, Spillman was ordered off the field with an hour remaining in practice. He walked slowly to the locker room with his pants ripped. Thomas remained on the practice field and took his typical number of reps during the remainder of the 2 1/2-hour practice.
Spillman opened training camp in what was described as a four-way competition for the starting job at safety. But Spillman has not seen many first-team reps in recent weeks. Rookie Eric Reid worked alongside Donte Whitner with the first-team defense on Tuesday.
Spillman is regarded as one of the 49ers' best special-teams players. He is considered a strong bet to make the team. Thomas spent last season on the practice squad.
Jenkins, meanwhile, did nothing to hurt his cause on Tuesday. He made a good catch on a deep out from quarterback Colin Kaepernick against the coverage of starting cornerback Carlos Rogers. He had a good catch along the sideline against Tarell Brown on the other side. He also demonstrated strong hands to haul in a 17-yard pass over the middle as cornerback Darryl Morris tried to rake the ball out of his grasp.
[RELATED -- Vernon Davis on Jenkins: 'He's got time']
Offensive play of the day: The 49ers are slowly working WR Kyle Williams back into the mix. On Tuesday, he made the best catch of the day when he ran a go-route along the right sideline against rookie CB Marcus Cooper. QB B.J. Daniels underthrew the pass. Williams slowed up and reached back while Cooper went up to contest the throw. Williams latched onto the reception 45 yards down the field and managed to get both feet inbounds. Williams was cleared to practice at the opening of camp after a season-ending knee injury. He missed five practices early in camp with a hamstring strain. He was held out of the 49ers' exhibition opener last week.
Worth noting: Bubba Ventrone was making a strong case for a roster spot because of his play on special teams. In the first game, he lined up as P Andy Lee's personal protector. Craig Dahl and Michael Thomas took over that role in practice Tuesday, as Ventrone is out with a hamstring strain. The 49ers will have a new personal protector this season because Dashon Goldson served in that capacity in recent seasons. . . RB Jewel Hampton, returning from a hamstring strain, saw a lot of action. The 49ers had a run-heavy opening portion of practice, during which time Hampton carried six times. . . Austin Collie led the wideouts with four receptions during the 11-on-11 periods. Marlon Moore and Anquan Boldin, who lined up with the first team, were the only wide receivers who did not catch a pass. . . TE Garrett Celek caught four passes. . . FS Trenton Robinson had a chance of an interception on a pass Tolzien overthrew, intended for Gray, but he dropped it. . . RG Wayne Tribue was pulled out of the huddle after he was guilty of a false start.
Rookie report: TE MarQueis Gray had his best day on the practice field, as he took full advantage of Vance McDonald's absence. Gray, a quarterback at the University of Minnesota, made a nice 26-yard reception of a Scott Tolzien pass between LB Nick Moody and safeties Darcel McBath and Thomas. He also had a nice grab of a Colt McCoy pass in which he reached over Whitner to pluck the ball out of the air 25 yards down the field. . . . During one-on-one drills, WR Quinton Patton was matched against Reid. Patton turned Reid around with a post-corner route and latched onto a one-handed catch 30 yards down the field on a throw from Kaepernick. Patton is nursing an injury to the index finger on his left hand, so he made the grab with his right hand.
New injuries: None.
Returning from injuries: CB Carlos Rogers (undisclosed), RB Jewel Hampton (hamstring).
Still sidelined: TE Vance McDonald (undisclosed), LT Joe Staley (undisclosed), S Bubba Ventrone (hamstring), CB Chris Culliver (torn left ACL), LB Patrick Willis (broken right hand).
Physically unable to perform list: WR Michael Crabtree (Achilles) and WR Mario Manningham (knee).
Non-football injury list: RB Marcus Lattimore (knee), DE Tank Carradine (knee), DT Quinton Dial (toe) and OT Luke Marquardt (foot)
[RELATED: Carradine, Dial not expected back soon]
Non-football injury/illness list: CB Eric Wright (undisclosed).
Quote of the day: "I don't imagine it gets much tougher than that. He's throwing 40 yards on a line, so you got to take a pretty sharp angle to get there to meet the ball. That's helping me out. I go into practice every day with the mindset of 'You got to get better.' Because Kap will make you look bad if you're not on your toes."
--49ers rookie FS Eric Reid on facing QB Colin Kaepernick in practices