SANTA CLARA -- The 49ers signed veteran free-agent quarterback Seneca Wallace on Thursday.
The 49ers waived wide receiver Ricardo Lockette, quarterback Colin Kaepernick's roommate and one of his best friends on the team.
Wallace joins a competition for the 49ers' backup job and also includes Colt McCoy, Scott Tolzien and rookie B.J. Daniels are now vying for the 49ers' backup job. He served two seasons at McCoy's backup with the Cleveland Browns in 2010 and 2011. The Browns' coach was Eric Mangini, who serves as 49ers senior offensive consultant.
McCoy's passer rating in the first two exhibition games is 25.3. He has completed just six of 13 pass attempts for 76yards with no touchdowns and two interceptions.
When asked if his unfamiliarity with the system is to blame for McCoy's problems, 49ers coach Jim Harbaugh said. "It's definitely a factor, and the good improvement this week, he's working at it very hard, it means a lot to him and it does to us, too. We're coaching him up the best we can and we'll keep striving for improvement each day."
Wallace, 33, did not play last season after the Browns cut him in training camp. He signed this offseason with the New Orleans Saints but was released on Monday.
In 2011, Wallace saw action in six games with the Browns, who were 0-3 in the three games he started. He completed 51.4 percent of his passes with two touchdowns and two interceptions. He rushed seven times for 70 yards.
Wallace played five seasons with the Seattle Seahawks, during which time he started 14 games. Wallace is a 59.2-percent career passer with 4,808 yards, 31 touchdowns and 18 interceptions.
Wallace, a native of Sacramento, was a star at Iowa State University, where he finished his college career as the school's record holder with 6,201 yards of total offense.
Lockette joined the 49ers last season as a member of the team's practice squad. Lockette went to Atlanta early in the offseason to work out with Kaepernick. The two men bonded and became close friends.
But Lockette faded into the background of a crowded competition at wide receiver. He did not catch a pass in either of the 49ers' first two exhibition games.