Lefty out of pro-am days after injury

Phil Mickelson will skip Wednesday's pro-am for the Shell Houston Open, raising the possibility he will miss this week's PGA Tour event just days after withdrawing from the Texas Open with a pulled muscle in his right side.

"We haven't heard a word from Phil, so we don't know whether he's playing or not," a PGA Tour official told the AFP, according to the Golf Channel. "All we know at this stage is that we had a call saying he [needed to] be excused from competing in the pro-am."

Mickelson withdrew from the Texas Open after 10 holes in the third round Saturday. He was 4 over overall at the time.

"I pulled a muscle on my downswing trying to hit it hard on the first hole," Mickelson said in a statement Saturday. "It just killed and it wouldn't subside for 10 or 12 seconds.

"I'm going back to San Diego [for] a couple of days and have a doctor look at it, but there's really not much you can do for a pulled muscle. I hope I'll be OK to play the Shell in Houston, but I just don't know."

PGA Tour players are allowed to skip two pro-ams per season.

The injury also could jeopardize Mickelson's status for the Masters, with the year's first major set to begin next Thursday.

The Masters field already took a hit Wednesday when Tiger Woods withdrew after having back surgery earlier this week.

If Mickelson does play Thursday at Houston, he will be paired with Keegan Bradley and Webb Simpson in the opening round.