Veteran defensive tackle Gary Walker, one of the high-profile performers selected by the Houston Texans in the expansion draft, might miss the franchise's entire inaugural training camp.

Team spokesman Tony Wylie said early Monday evening that Walker will meet with a specialist Tuesday and that the Texans "will have a better idea then" of how to proceed in treating a serious groin injury suffered last Thursday in a so-called "coaching" session.

But agent Pat Dye Jr. told ESPN.com that Walker, 29, is tentatively scheduled to undergo surgery Thursday to repair the groin injury and also a pre-existing hernia. The hernia was detected during an MRI exam last Friday. A second MRI on Monday confirmed, Dye said, that the groin injury also required surgery.

"The feeling is that it's better to go in and do the surgery now and get him ready for the season," said Dye. "But it looks like he'll miss the better portion, and maybe even all, of camp. The (groin) injury was a pretty serious one."

A seven-year veteran, Walker is being counted on as one of the cornerstones of the 3-4 defensive front that coach Dom Capers will employ. It had not yet been determined if Walker, who has played tackle in a conventional 4-3 scheme, would play tackle or end for the Texans.

Walker was taken off the field last Thursday after suffering the injury. He said the groin injury, which he called a "freak" occurrence, was likely a severe one.

The injury to Walker is the third significant setback this offseason for the first-year franchise. Offensive tackle Tony Boselli, the club's first choice in the expansion draft, recently had surgery on his left shoulder and could miss a portion of training camp as well. Wide receiver Jermaine Lewis suffered a severe hamstring pull this spring.

Walker started all 16 games for the Jacksonville Jaguars in 2001, his third season with the team, and had 73 tackles and 7½ sacks. He made his first Pro Bowl appearance last season.

For his career, Walker has appeared in 109 games and started 102 of them. He has posted 411 tackles and 38½ sacks.

Len Pasquarelli is a senior writer for ESPN.com.