The 49ers are not finished shopping for a defensive lineman.
A league source confirmed the team is battling the Chicago Bears for free agent defensive lineman Israel Idonije. The 32-year-old lineman started 11 games last season as a defensive end in Chicago's 4-3 defense, finishing with 48 tackles and a solid 7 Â½ sacks. NFL.com was first to report the 49ers' interest. Idonije had a half sack in a 32-7 loss to San Francisco this past season.
San Francisco presumably is looking at the 6-6, 275-pounder to play defensive end in its 3-4 scheme. It's a position the 49ers have been examining during the offseason having already looked at Cullen Jenkins and Desmond Bryant, who ended up signing with the Giants and Browns respectively.
The team's interest in linemen could signal more platooning along the defensive front than occurred in 2011 and 2012 when the starters - when healthy - played virtually every snap. The 49ers' pass rush waned late in the season and into the playoffs.
Through Week 14, the 49ers had 35 sacks, an average of 2.5 per game. After that, they averaged 1.4 sacks per game. Week 14, of course, is when defensive end Justin Smith tore his triceps tendon. He didn't have any sacks in the playoffs and neither did linemate Aldon Smith, who apparently was dealing with a labrum injury at the time.
-- Matt Barrows