Running back Doug Martin is expected to play Sunday, but the Tampa Bay Buccaneers still want to test him prior to their game against the Chicago Bears, sources told ESPN on Saturday.

Martin has not played in a game since suffering a hamstring injury in Week 2. He attempted to come back just prior to the Week 5 game against the Carolina Panthers, but he reinjured the hamstring during a workout.

He was limited in practice all week, and the Bucs were not optimistic he would make it through the week. However, Martin's steady improvement in the practices offered an encouraging sign.

After rushing for 1,402 yards last year, second-most in the league, with six rushing touchdowns and a receiving touchdown, Martin's 4.9 yards-per-carry average has fallen to 2.9 in 2016. Getty Images

While the rest of his teammates were warming up during Friday's practice and doing special-teams work, Martin did some resistance runs with head athletic trainer Bobby Slater, pulling a large rubber band behind him. He's gone from doing individual drills Wednesday to pass-catching work with the quarterbacks and cutting Thursday.

Bucs coach Dirk Koetter on Friday said Martin still had not been cleared by the medical staff.

"There's still a chance," Koetter said, adding that the team would "see what happens" within 48 hours.

A two-time Pro Bowler, Martin rushed for 1,402 yards last season, second-most in the league behind Adrian Peterson. He also had 271 receiving yards and accounted for 28 percent of the Bucs' total offense last year. His seven touchdowns were more than any other player on the team, aside from Jameis Winston.

The Bucs have struggled to run the ball consistently in their run-first offense this season, averaging 108.0 yards per game -- 20th in the league. Their 3.9 yards-per-carry average ranks 23rd. Last year, with Martin and Charles Sims healthy, the Bucs produced the fifth-most rushing yards in the league, with 135.1 yards per game. Their 4.8 yards-per-carry average was tied for first in the league.

If Martin cannot go, the team has rookie Peyton Barber, who started his first NFL game last week, and Mike James, whom the Bucs re-signed last week. James has three prior starts for the Bucs.

To make room on the roster, the Bucs waived Russell Hansbrough, who was brought up from the practice squad Monday.

Jacquizz Rodgers, the fourth running back on the active roster, continues to recover from a sprained foot and is still in a walking boot.