SANTA CLARA -- Kenneth Acker and Keith Reaser will compete during the course of the week to open the regular season Monday night against the Minnesota Vikings as one of the 49ers’ starting cornerbacks, coach Jim Tomsula announced on Tuesday.
"Acker has done a great job, but Reaser is in the mix," Tomsula said.
Acker and Reaser emerged ahead of Dontae Johnson and Shareece Wright for a possible starting role. Tomsula said the starting cornerbacks could change from week to week, depending on the matchups.
"You will see throughout the year, matchup-wise you’ll see us matching up the way we need to matchup with those guys, between those three," Tomsula said, adding Johnson into the conversation. "But Acker has really come on and done a great job. If you want somebody that’s going to be on a depth chart, it’ll probably say Reaser and Acker through the week.”
The 49ers kept five cornerbacks on their regular-season roster. Tramaine Brock, the starter on the other side, Wright and Johnson are the only 49ers cornerbacks who have seen regular-season action in the NFL.
Reaser, a fifth-round pick last year, spent his entire rookie season on the non-football injury list after undergoing two surgeries following a career-ending ACL injury as a senior at Florida Atlantic. Acker, a sixth-round pick last year, spent the season on injured reserve with a stress fracture in his foot.
Brock is scheduled to start on the other side after putting together a strong camp. Brock opened last season as the starter but played less than 10 healthy snaps all season. He sustained a turf toe injury early in the 49ers’ season opener agains the Dallas Cowboys. Brock was sidelined with a hamstring injury later in the season.
Brock is expected to be at full strength for the season opener after sustaining a minor hamstring pull two weeks ago during warmups as the team prepared to practice against the Denver Broncos.
Wright started 27 games the past two seasons with the San Diego Chargers. Wright signed a one-year, $2.95 million contract as a free agent this offseason. Johnson, a fourth-round draft pick in 2014, started three of the 16 games in which he appeared last season.