Peterson's absence gave him a chance to recover from a dislocated toe on his left foot.
Peterson has missed many practices, first with a dislocated toe and more recently because of the concussion he sustained in Houston on Nov. 24.
Gatland feared that second-row Jones, 26, would miss all the Six Nations matches after having surgery on a dislocated big toe.
This was accomplished by Dallas without defensive tackle Russell Maryland, who missed the game due to a dislocated toe.
Oakley, who missed his fourth consecutive game, said he will have surgery soon if his dislocated toe does not improve.
Charles Oakley, the team's leading rebounder and best low-post defender, has missed the last three games with a dislocated toe that may require surgery.
He has played spectacularly, even when hampered in Weeks 2, 3 and 4 by a dislocated toe.
In Jarakay, Niña had to do the same thing because of what she thought was a dislocated toe that she attained during the Reward Challenge.
There is the health of Ewing and Charles Oakley, who is playing with a dislocated second toe on his right foot.
Szczerbiak is expected to be out at least a few more days with a dislocated left toe.