SANTA CLARA Eric Reid, the 49ers' first-round draft pick, likely will make his first start at free safety Sunday against the Vikings, defensive coordinator Vic Fangio said Monday.
Reid has played well in two preseason games, including some action against the Chiefs' first-string unit.
Craig Dahl has been the starter, but Fangio said Reid "probably" would play with the first-string defense against Minnesota.
"He's close," Fangio said of Reid taking over the starting job. "He's done well all camp. We'll probably start him in this game coming up and see how he does with that."
Said Reid: "My goal every day is just to get better at something. And that's something that (veteran cornerback Nnamdi Asomugha) talked about today at practice: As long as you focus on getting better at one thing a day, it accumulates. And that's what I've been trying to do, and hopefully that's leading me into getting a starting job."
Fangio also said there has been some separation in the competition between Tramaine Brock and Asomugha to replace injured Chris Culliver as the No. 3 cornerback.
Brock had the first chance to win the job, but Asomugha has looked good in recent practices and in Friday's game in Kansas City.
Fangio wouldn't say which cornerback had the lead, but he complimented Asomugha earlier in Monday's news conference when he was asked about Asomugha's coverage on a deep attempt from Chiefs quarterback Alex Smith to Jon Baldwin, who was acquired by the 49ers on Monday for A.J. Jenkins.
"He was in good shape there, and our free safety, C.J. (Spillman), was in good shape in the middle of the field, and the quarterback overthrew it," Fangio said. "But we were in good position there. We had a chance to make the play if the ball were thrown better."
Fangio said the 49ers would keep five or six cornerbacks on the active roster, but he said he had "no idea" how Eric Wright, who is on the non-football injury/illness list, figures into that mix.
Wright hasn't joined the team as he deals with a personal issue. "You guys know as much about that as I do, to be honest with you," Fangio said.
Et cetera Rookie wide receiver Quinton Patton, back to practicing in full this week, said he broke his finger before training camp on a pass from Colt McCoy, not one from Colin Kaepernick.
Rookie tight end Vance McDonald missed his seventh straight practice Monday with an undisclosed injury. McDonald was the team's leading receiver in the preseason opener against Denver but didn't play against the Chiefs.
Baldwin arrived in Santa Clara on Monday evening and is expected to join the team for today's practice.