WICHITA FALLS, Texas (AP) _ Raghib ``Rocket'' Ismail's debut with the Dallas Cowboys is on hold as the receiver slightly separated his left shoulder Wednesday.

``We're calling it day-to-day, but it looks like it'll be closer to a week before we actually get him back on any type of full-time basis,'' coach Chan Gailey said.

Gailey said Ismail definitely will not play Monday night in the team's exhibition opener, the Hall of Fame game against the Cleveland Browns in Canton, Ohio.

Ismail was injured while trying to catch a pass in a morning workout.

``I saw it and it didn't look so bad, so I wasn't that concerned,'' Gailey said.

Ismail joined the Cowboys as a free agent in April. The former Oakland Raiders and Carolina Panthers player cashed in on the two best seasons of his career by signing a $21.5 million, seven-year contract.

The Cowboys are counting on Ismail's speed from the slot position to help open things up in their offense.

Quarterback Troy Aikman said Ismail is the fastest, most polished receiver he's had in Dallas.

``We've had other guys with that speed before, but they've been projects, guys who we were just hoping could come in and provide us with a weapon,'' Aikman said. ``He's shown he can play in this league.''

If Ismail heals in a week, the soonest Aikman and Ismail could hook up in a game is Aug. 15 in Oakland.

Having Ismail line up inside allows the Cowboys to keep Michael Irvin outside, where he's thrived most of his career. Irvin has said he ``felt like a rookie'' playing the slot last year.

Until Ismail returns, he'll be replaced on the first team by Ernie Mills, who is recovering from a November injury that ended his 1998 season.