IRVING, Texas -- Dallas Cowboys defensive tackle Jay Ratliff's long absence just got a little longer.
Ratliff will miss at least the first six games of the season after he was placed on the physically unable to perform list with hamstring and groin injuries. The Cowboys made the move Tuesday as part of getting their active roster down to 75 players.
Ratliff, who turns 32 Thursday, missed off-season workouts and training camp after sports hernia surgery late last season. He missed 10 games in 2012 with ankle and groin problems. He last played Nov. 18 against Cleveland.
Dallas cut nine players and placed defensive end Tyrone Crawford and lineman Ryan Cook on season-ending injured reserve.
The released players were receivers Anthony Amos, Jared Green and Eric Rogers, quarterback Nick Stephens, tight end Colin Cochart, guard Dennis Godfrey, linebacker Deon Lacey, cornerback Brandon Underwood and kicker Brett Maher.
Cowboys executive vice-president Stephen Jones said he was confident Ratliff would play this season.
"I believe in Jay," Jones said before the move with Ratliff was announced. "There's some things that can be frustrating when you have injuries. I'm convinced that we've got a program now -- he's had a few setbacks -- that hopefully will put him on the road where he can play for us at some point this season."
Ratliff has only two sacks since signing a seven-year, $49 million contract with $18 million guaranteed two years ago. He will have missed 16 of 22 games by the time he's eligible to return Oct. 20 at Philadelphia.
"The groin injury has been the one he's been dealing with mostly through all of last year and through the off-season, so I think the biggest issue with him is regaining his strength," coach Jason Garrett said. "Strength enough to go out on the field and do the things he needs to do to anchor and change direction and all the things that are required to play his position."
With Ratliff sidelined, the Cowboys could be forced to play the opener Sept. 8 against the New York Giants without both starters on the left side in their new four-man defensive front. Left end Anthony Spencer is recovering from knee surgery.
George Selvie, a four-year veteran who didn't join Dallas until after training camp started, has taken Spencer's place. Nick Hayden, a sixth-year pro who was out of football last season, started in Ratliff's spot in last weekend's preseason game against Cincinnati.
"He's done a very good job for us since he's been here," Garrett said. "He shows up as a playmaker in the run game and also affecting the quarterback in the pass game."
The release of Stephens means Alex Tanney will get most or all of the playing time in the final preseason game Thursday night against Houston. The Cowboys didn't sign Tanney, a second-year player out of Monmouth College in Illinois, until the start of training camp and need to decide whether to keep a third quarterback behind Tony Romo and Kyle Orton.
Rogers made a strong early impression in training camp in Oxnard, Calif. -- not far from his college home at Cal Lutheran -- but didn't have a catch in four preseason games. Green, the son of former Washington Redskins star and Hall of Fame cornerback Darrell Green, and Amos had three catches apiece in the preseason.