OXNARD, Calif. — Quarterback Tony Romo, who spent the off-season recovering from minor back surgery, started camp a little rusty but is getting stronger by the day, Dallas Cowboys coach Jason Garrett said.The team’s first training camp practice Sunday was Romo’s first since Dec. 28. He missed three months after having a cyst removed in April and only recently began throwing again.The Cowboys are monitoring Romo to make sure he doesn’t get “camp arm” early.“He’s getting better every day,” Garrett said. “Clearly, when he first started practicing on the first day he wasn’t quite himself. The second day was better, and the third day was better. He’s moving around. You see him getting away from the line of scrimmage. You see him reacting like he normally reacts. The ball’s coming out of his hand better. He’s just not quite as stiff. “He hasn’t been in this environment for a while, so I think that’s natural to think that. But he’s responded well with the work. We’ve monitored his throwing a little bit in the individual periods. He’s not getting the exact rotation when we’re just throwing routes on air. He’s getting a chance to throw to Miles [Austin] and Dez [Bryant] and some of the other first-tier guys. But he’s responding well to everything, and I think he’s getting better every day.”Ratliff still outWhen defensive tackle Jay Ratliff strained his hamstring in conditioning drills and was placed on the physically unable to perform list, the Cowboys said they weren’t concerned and expected him to make his training camp debut sooner than later.One week into camp, sooner is starting to look like later. But the Cowboys are remaining patient, optimistic and unconcerned.Jason Garrett said Ratliff is at least two weeks away as the Cowboys are playing it safe because of the injuries that caused Ratliff to miss 10 games last season.“He’s in rehab and doing all the stuff he needs to do but we don’t anticipate him being on the field at least until next week and it might be a couple of weeks,” Garrett said. “But again, it’s still early. We play the extra preseason game, we are here a week earlier than everyone else, so we are going to err on the side of caution with those guys.“Most recently it is the hamstring but we were going to be cautious with him with regard to his groin and the other issues he had last year. He looks good. He’s working hard but he’s got to take it day by day and hopefully he will be back soon.”Added depthThe Cowboys added a pair of defensive linemen to help them get through training camp while they are short-handed because of injuries to Jay Ratliff, Anthony Spencer, Tyrone Crawford and Ike Igbinosun.Defensive tackle Landon Cohen and defensive end George Selvie were signed, and receiver Lavasier Tuinei was released.Spencer is expected to have minor knee surgery in Dallas later this week and will be sidelined at least a month. Crawford is out for the season with a torn Achilles and Igbinosun is day-to-day with a foot injury.Cohen has four years in the league, with Detroit, Jacksonville and New England. He played in 14 games and started four for the Lions in 2009.Selvie has three years in the NFL with three teams — St. Louis, Carolina and Jacksonville. He has not started a game.Tuinei, a receiver out of Oregon, did not pass the conditioning test at the start of training camp.