For Bears defense, the shift is on

Most of the Bears' ends from last year's 4-3 defense will be asked to convert to outside linebackers in the new 3-4 scheme, so they will have to be replaced by bigger players.

In most 3-4 defenses, the ends are not required to be strong pass rushers but must control the line of scrimmage, occupy blockers and contain the run. So Jared Allen, Lamarr Houston, Willie Young and David Bass will all get their first looks at outside linebacker when the off-season program picks up steam with a three-day voluntary minicamp that leads into the first round of the draft on April 30.

With the exception of the bulkier Houston, the others in that group all played at between 250 and 260 pounds last season.

In their place at defensive end will be unrestricted free agents Ray McDonald and Jarvis Jenkins, who are expected to line up as the starting defensive ends. The 6-foot-3, 290-pound McDonald is an eight-year veteran who was an integral part of the San Francisco 49ers' defenses that were among the best in the NFL the past four years. McDonald had 14 ½ sacks during that time, starting 59 games.

A four-year veteran, Jenkins isn't the pass-rush threat that McDonald is, but at 6-foot-4 and 315 pounds he can anchor one side of the line vs. the run.

It's uncertain where 6-foot, 303-pound Will Sutton, last year's third-round pick, fits in the new defense, but it could be as a 3-technique tackle in nickel alignments when the Bears shift into a 4-3.

Nose tackle is a question mark for now. Many 3-4 schemes require bigger players at nose than those currently on the Bears' roster - 303-pound Jeremiah Ratliff and 315-pound Ego Ferguson.

But new defensive coordinator Vic Fangio utilized much smaller nose tackles over the last four seasons when his 49ers defenses were among the league's best.

Still, it would be surprising if the Bears don't come out of the draft without a big-bodied, space-eating run stuffer for the nose tackle spot.