Vice-president Stephen Jones said the injuries at guard have the Cowboys looking at all their options to find the best five players on the offensive line.
After striking out with free agent guards Brandon Moore and Brian Waters, the Cowboys have now turned to looking at right tackle Doug Free at right guard with Jermey Parnell at tackle.
The Cowboys are hoping that guard Ron Leary, who underwent arthroscopic knee surgery last Friday, is back for the season opener against the Giants on Sept. 8.
But there are no guarantees and they need an alternate plan in place, which is why Free will get snaps at guard against the Bengals Saturday.
"It's no secret we are looking at all our options," Jones said. "We are hoping for Leary and feel good about him. But we don't know. We want to get the best five on the field."
The Cowboys have been working rookie center Travis Frederick at guard. But they don't like the option of using Phil Costa at center and Frederick at guard.
"Frederick is doing so well at center and he's a rookie, we don't want to move him," Jones said.
Jones said this option is contingent on how well Parnell plays at tackle after missing much of training camp with a hamstring. He will be making his preseason debut against the Bengals on Saturday.