SANTA CLARA, Calif. - 49ers head coach Jim Tomsula is continuing to tinker with his team's starting offensive line as it heads into its third preseason game.
At practice Tuesday, hours before the team departed for Denver for two joint practices with the Broncos before Saturday's exhibition, rookie seventh-round pick Ian Silberman was inserted at right guard with the first team.
To this point, Marcus Martin, Brandon Thomas and Silberman have all gotten first-team practice reps at right guard. Martin switched from right guard, where he started the first two preseason games, to center.
"We are not settled there. We’re getting closer," Tomsula said in a conference call Monday.
It remains to be seen if Silberman will get the nod Saturday against the Broncos. He received positive reviews from his head coach after his performance in Sunday's 23-6 win over the Cowboys, when San Francisco rushed for 155 yards. Joe Looney, who started at center in both preseason games, worked with the reserves Tuesday.
After playing well at right guard against the Texans in the first preseason game, Thomas has moved back to left guard, where he did the majority of his work in the offseason. General manager Trent Baalke in the spring said Thomas was drafted with replacing departed free-agent Mike Iupati in mind. But he got work on the right side in training camp because of a minor leg issue, Tomsula said.
"As we were going through the process of getting back on the field and working through things, we noticed there was a little hitch in his giddy-up," said Tomsula. "The way the steps timed out, on that third step was that leg, so we put him to the right, to try to get that hitch out of the giddy-up and it worked really well. So we’ve seen him moving great."
While Tomsula has gone with the same starting five in the first two preseason games, he maintains the competition at center and right guard remains fluid.
The same can be said for cornerback.
After missing all of 2014 with a stress fracture in his foot, second-year cornerback Kenneth Acker moved into the first team during Tuesday's practice on the right side opposite Tramaine Brock. Acker replaced Keith Reaser, who started against Dallas, after taking over for Shareece Wright, who started in Houston.
This preseason Acker has allowed three receptions on five targets, according to Pro Football Focus. Reaser allowed four in six targets, while Wright allowed two catches in two targets, including a two-point conversion to Texans receiver DeAndre Hopkins.
Last year's first-round pick Jimmie Ward continued to work with the reserves back at his natural position of safety, while Brock continues to get the majority of reps with the first team at nickel cornerback. Ward didn't play against the Cowboys, but appears in line to play Saturday in Denver.
Wilhoite said he expects to play Saturday, but is unsure how much. His insertion into the starting lineup Tuesday indicates he's the favorite to earn the starting spot when the regular season starts after being the only 49ers linebacker to start all 16 games last season.
Receiver Torrey Smith was held out of team drills after suiting up for practice while dealing with minor knee soreness, the 49ers said. Bruce Ellington (muscle strain) returned to the practice field, as expected, but his reps were limited.
Defensive lineman Glenn Dorsey was back on the field after missing the majority of the last two weeks with a muscle strain. He was held out of team drills. Tony Jerod-Eddie replaced him in the starting unit at left defensive end. Nose tackle Mike Purcell saw a few reps in nickel Tuesday after playing well in the first two preseason games, including Sunday's interception returned for a touchdown.
"I thought he did very well, and I would expect you to see him playing a little earlier," Tomsula said of Devey's play Sunday.
According to Pro Football Focus, Devey played both guard spots with the Patriots last season, but never center.
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