JACKSONVILLE, Fla. -- Uncertainty continues to plague the Jacksonville Jaguars' offensive line, which makes it difficult to put together a consistent running game or reliable pass protection.

That was further complicated Friday when it was learned that starting right tackle Austin Pasztor suffered a broken hand and would be out at least a month.

That likely means journeyman Cameron Bradfield will step in at the position, much like he did a year ago when he started the final 11 games of the season when the Jaguars lost Luke Joeckel to a season-ending fractured right ankle.

The Jaguars are still looking for the right combination at right guard and center among three players -- Mike Brewster, Jacques McClendon and Brandon Linder.

Bradley said all three players played well against Chicago but singled out Linder for his strong play. He indicated that the rookie from Miami would likely start at one of the two positions. If it's the guard spot, Brewster would be the starting center. If Linder moves to the center spot, McClendon would get the starting call at guard.

The Jaguars are so uncertain about their play at center that they signed fifth-year center Antoine Caldwell earlier in the week. A third-round pick by Houston in 2009, Caldwell competed in the Jaguars' minicamp in May. He played in 39 games for the Texans with 19 starts during a four-year period (2009-12). He later spent time with Buffalo during the 20013 season.

His signing might prove to be valuable as rookie center Luke Bowanko suffered an ankle sprain in the Chicago game and was to have an MRI done late on Friday to determine the severity of the injury and how long he might be out.

It took just one running play for Toby Gerhart to excite Jaguars fans. Gerhart missed the team's first preseason game when a hip flexor injury cost him 11 days of training camp. And while his production was basically limited to just the first quarter against Chicago, Gerhart showed enough with a burst through the middle that netted 18 yards for the team's longest running play of the game.

Gerhart finished with 19 yards on six carries, due to two runs on which he was stopped for negative yardage when two of the Jaguars' offensive lineman were both overpowered on plays that resulted in Gerhart going down behind the line of scrimmage.

"I was excited, maybe a little overexcited," he said at halftime. "It was great to be back out there and put on a Jaguars jersey for the first time. I think I tried to do too much and missed one or two (plays) out there."