Garcia was hurt on the first play of Sunday's 19-13 victory over Washington. He left the game two plays later and remained on the sideline until the Redskins trimmed a 16-point halftime deficit to six early in the fourth quarter.
Coach Jon Gruden described the injury as a lower back bruise. He said the three-time Pro Bowl selection's status is day to day.
"He might be ready to go Wednesday (for practice). He might not be. He might be ready to go against the Saints. He might not be. We'll deal with that on a day-to-day basis."
Garcia, one of the big reasons the Bucs (7-4) lead the NFC South by two games, has not started every game in a season since 2002 with San Francisco. He's in his first year with the Bucs after spending the past three with Cleveland, Detroit and Philadelphia.
Gradkowski started 11 games as a rookie after Chris Simms suffered a season-ending spleen injury last year. He replaced Garcia against Washington, but was unable to consistently move the offense.
The Redskins lost four fumbles inside their 35 in the first half, yet the Bucs were only able to convert them into a touchdown and three field goals.
It was even uglier in the second half, when Tampa Bay was outgained 316 yards to 15 and failed to make a first down. Garcia paced the sideline while a 19-3 lead gradually was closed to six points, then persuaded Gruden to send him back onto the field with just over 11 minutes remaining.
Garcia, hurt when he scrambled for a 1-yard gain and was tackled by Washington's Cornelius Griffin, was not available for comment Monday. After the game, he said he was optimistic he would play against the Saints.
"I feel like I can heal fast," he said. "I'm going to listen to my body and allow it to tell me how I should take it."
Garcia has completed 64.5 percent of his passes for 2,135 yards, 11 touchdowns and three interceptions in 11 games. He has the third-highest passer rating (96.0) in the NFC behind Tony Romo and Brett Favre and didn't throw an interception until the eighth week of the season.
The quarterback may not necessarily have to practice Wednesday and Thursday to get the start against the Saints (5-6).
"He can play, no question, with reduced practice snaps," Gruden said. "We practice, though, to get guys ready to play. Again, I don't want to speculate."
Copyright 2007 by The Associated Press