OXNARD, Calif. -- Dallas Cowboys left guard Kyle Kosier is expected to miss at least one month after spraining his knee, meaning the team has lost two offensive linemen to injuries this week.
Kosier was hurt Wednesday morning, two days after right tackle Marc Colombo underwent knee surgery.
Although the team was still waiting for results of an MRI exam on Kosier, Cowboys coach Wade Phillips said it appears to be the same injury that has sidelined defensive lineman Marcus Spears for four to six weeks. That timeframe means Kosier likely will miss the Sept. 12 season opener at Washington and perhaps as many as the first three games. The Cowboys have a bye in the season's fourth week.
"When it's not a season-ending injury, it makes you feel better," Phillips said. "These guys are going to come back. We'd like to have them all right now, but we don't. That's part of what goes on. ... If it's similar to Spears, that'd be fine. If it's less than that, it'd be great."
Veteran Montrae Holland took Kosier's place during the morning workout and is expected to start in Saturday night's preseason game at San Diego.
Robert Brewster, a second-year pro who missed last season with an injury, has been filling for Colombo since he went down Sunday. Colombo underwent arthroscopic surgery Monday to remove five loose particles in his knee. He's expected to miss two weeks and return in time to start the season opener.
"Our attitude has to be the same no matter what: protect our quarterback, help the running game and play well," Phillips said. "I feel good about the group we have. ... I think it was smart that we have the veteran players like we have and also the young players coming up. We'll see about our depth, but I think we have a lot of depth in the offensive line."
Is the reward -- Tony Romo working on his timing with Miles Austin, Roy Williams and Jason Witten -- worth the risk of him being hurt because of a missed block?
Phillips believes so.
Pressed about Romo, Phillips declared, "He'll play," and said starters will play more than they have in the first two preseason games.
"They need to play as a team," the coach said.
Cowboys owner Jerry Jones wholeheartedly agrees. He also made it clear that he's not at all worried about left guard, saying: "Holland is paid what he's paid ($3.7 million base salary over two years, with the chance to make $5.2 million) in case we don't have Kosier."
Brewster, Jones said, is "a horse of a different color."
"He's a rookie for all practical purposes," Jones said. "Everybody keep an eye on that right there. There will probably be some additional help in there, with extra (tight ends)."
Brewster might be a stop-gap solution. Offseason acquisition Alex Barron is almost recovered from an ankle injury and could play Saturday night. He might be the second-string left tackle against the Chargers, then take over at right tackle next week.
"He just told me he wants to play -- he feels good," Jones said. "If Barron is ready and does want to -- he said he did -- they told me he's in good enough health to do it."
Holland is recovering from an injury, too. A hamstring problem kept him out of the first two preseason games, but he knows what he's doing: This is his third season with Dallas and eighth in the NFL. He has played in 74 games, starting 48, including all 16 in 2007 with the Denver Broncos and two for the Cowboys in '08.
"We certainly like Marc Colombo and Kyle Kosier, and we want them out here practicing, but it gives other guys an opportunity to step up and show that they can do," Cowboys offensive coordinator Jason Garrett said. "One of the things we preach to our players all the time is adversity -- there's going to be a lot of different kinds of adversity, and injuries is one of them. The backup players we have here have to step up and do their jobs, show they're worthy of being starting players or prominent backup players on our football team."
Kosier is slated to be the backup center, and he was playing center when he was hurt.
"It was a freak accident," Phillips said. "It could've happened at guard."
Colombo's injury fueled questions about whether a line featuring four guys in their 30s is too risky. Kosier's injury strengthens the argument that the group is too old, making them too susceptible to injury.
Cowboys owner Jerry Jones insisted experience is more important, especially for a team that's expected to be a contender. Line coach Hudson Houck agrees, noting that "those things happen whether you're young or old."
"Now, with Kyle out, we've lowered our average age," Houck said. "Is that good? No, let's get him back in there and get that age up."
Copyright 2010 by The Associated Press