Here's a matchup to watch in Sunday's Browns-49ers game.

Browns RBs Montario Hardesty, Chris Ogbonnaya and Peyton Hillis vs. 49ers ILBs Patrick Willis and NaVorro Bowman

If healthy, Hillis would be the focal point of this discussion from a Browns perspective. However, the bruising tailback has a hamstring injury that kept him out of practice on Thursday and Friday, throwing his availablity for Sunday's game at San Francisco into doubt. Hillis, whom head coach Pat Shurmur said was able to run inside the club's facility on Friday, is listed as questionable on the injury report.

If Hillis is out, Hardesty, who racked up 95 yards on 33 carries in place of the injured Hillis last week in the 6-3 win vs. Seattle, will start, with Ogbonnaya spelling him. Hardesty (6-0, 225) has rushed for 238 yards on 73 yards this season (3.3 ypc). He is a grinding, straight-ahead runner who has a little more initial quickness than Hillis but lacks Hillis' power. Ogbonnaya, signed off Houston's practice squad last week, rushed for 15 yards on three carries and caught five passes for 43 yards vs. Seattle in his first game as a Brown. The 6-0, 225-pound Ogbonnaya appears to be a capable fill-in when Hardesty needs a rest.

Hardesty has taken care of the ball this season, fumbling just once in 85 touches. If the Browns are to pull off the upset, he will have to run hard, protect the ball and make the most of his opportunities against a stout run defense. With the Browns lacking big-play ability on offense, good execution is all the more important.

The 6-1, 240-pound Willis is one of the NFL's top defensive players. Willis (47 tackles) has sideline-to-sideline speed. Bowman (6-0, 242) has been a revelation. He leads the 49ers with 52 tackles (41 solo). The rangy Bowman has a knack for being around the ball.

The duo has combined to recover three fumbles, and Willis also has one forced fumble. The 49ers, who are allowing just 74.7 rushing yards per game and 3.58 yards per carry, have a stout defensive line and tough outside linebackers, and their ILB tandem has been exceptional. The Browns' running game gets a big test on Sunday.