SANTA CLARA -- Jim Harbaugh wore his cleats to his evening practice Friday. It was a wise choice.
The 49ers coach found himself having to move quickly and maintain his footing as he snuffed out two dustups, including one that resulted in Anquan Boldin, the coaches choice for MVP last season, being sent off the field.
Feisty behavior had been bubbling for several days.
The 49ers had had four straight days of fully padded practices before working in shells Thursday. They were back in full pads Friday, and they had their first live tackling drills of the offseason. There were several incidents of extra shoving throughout the session.
Harbaugh had to intercede midway through the practice to break up a potential fight between linebacker Chase Thomas and running back Jewel Hampton, who took exception to what he thought was a rough hit by the linebacker.
Then during a two-minute drill at the end of practice, quarterback McLeod Bethel-Thompson threw to Boldin on the left side of the formation. He went back in Boldins direction on the right side for a second completion and cornerback Darryl Morris went to wrap him up.
Boldin didnt like it. He tossed the ball at Morris, and when Morris approached him, he gave the young cornerback a fierce two-handed shot to the facemask. At that point, Harbaugh threw his body between the combatants and sent Boldin, an 11-year veteran, off the field.
Harbaugh has done that in the past. He doesnt like fighting or when teammates take each other to the ground unnecessarily. It runs counter to the protective family atmosphere he wants to build at 49ers headquarters. Hes said in the past that his players should be looking out for one another, not fighting.
The practice ended two plays after the Boldin-Morris melee when rookie cornerback Dontae Johnson undercut Bethel Thompsons pass to receiver Devon Wylie for an interception..
The 49ers have a day off today.
Dorsey injured The 49ers are down to one true nose tackle after veteran Glenn Dorsey went off the field with an injury to his left arm. A member of the teams medical staff spent time flexing Dorseys arm and appeared to be looking at his biceps or elbow.
Dorsey did not return to practice and the severity of his injury is not known.
The team already is without Ian Williams, who suffered a season-ending broken ankle in Week 2 last year. Second-year player Mike Purcell filled in at nose tackle for the rest of practice. Quinton Dial and Tony Jerod-Eddie also could play nose tackle if called upon.
By the end of practice, the 49ers had five defensive lineman on hand. Justin Smith (shoulder), Ray McDonald (leg) and rookie Kaleb Ramsey (knee) currently are not practicing. Demarcus Dobbs has been attending a personal matter for the last three days.
Injuries Harbaugh said that veteran wide receivers Michael Crabtree and Brandon Loyd might miss one or two weeks. Both are dealing with minor muscle strains. Neither is likely to play in Thursdays preseason opener in Baltimore.
Running back Marcus Lattimore (knee) remains on the non-football injury list, and Harbaugh did not provide a time line for his return.
Marcus is going to be part of this team in some form or fashion, Harbaugh said.
Read Matt Barrows blogs at www.sacbee.com/sf49ers