Bears offseason roster breakdown: Offensive line

Here is the first of eight positional breakdowns of the Chicago Bears' offseason roster following the NFL draft.

Position: Offensive line

Notable additions: center Will Montgomery, guard Vladimir Ducasse and center Hroniss Grasu (third-round pick)

Notable subtractions: center Roberto Garza and guard/tackle Eben Britton

Summary: Outside of Garza’s offseason departure, the offensive line isn’t expected to undergo too many radical changes. Two-time Pro Bowl right guard Kyle Long and left tackle Jermon Bushrod should return to their customary spots in the starting lineup, although Long has the ability to eventually move outside to tackle if necessary. Veteran left guard Matt Slauson is completely recovered from a torn pectoral muscle that caused him to miss the final nine games of 2014 -- Slauson also missed three games last season due to a high-ankle sprain. When healthy, Slauson is an above-average NFL guard and is a strong contender to retain his starting job. Montgomery, 32, who played for head coach John Fox and offensive coordinator Adam Gase in Denver, is likely to start at center, barring injury. However, Grasu represents the future at the position and should be active every week in the regular season, at the very least. After a promising rookie season in 2013, right tackle Jordan Mills took a step backward last year as he battled through a nagging foot injury. There have been no signs of trouble for Mills so far in the voluntary offseason program, but right tackle still remains somewhat of a question mark. Mills could be pushed in training camp by versatile offensive lineman Michael Ola, who started 12 games in 2014 (six at left guard, two at left tackle, three at right tackle, one at right guard). Charles Leno Jr., a 2014 seventh-round draft choice, is also in the mix for a roster spot after appearing in six games (one start) his rookie year. So is Ducasse, who started 11 games from 2010-14 for the New York Jets and Minnesota Vikings.