Mickelson Tees it up Thursday

After withdrawing because of injury last Saturday midway through the third round of the Valero Texas Open, Phil Mickelson was unsure he'd be playing this week in the Shell Houston Open.

It wasn't until Wednesday evening that Mickelson, who pulled an oblique muscle in his right side that caused him to walk off TPC San Antonio after 10 holes, said he was a "go" for Houston, the final tournament before the Masters.

"I feel that to give myself the best chance at the Masters I have to play in Houston," Mickelson said on his website. "If I thought I would injure myself further I would have withdrawn from the tournament, but the last few days have been good."

Mickelson didn't play in Wednesday's pro-am, adding to the idea that he might not play in the tournament he won in 2011. But he had a prior arrangement to take part in a sponsor's dinner rather than play in the pro-am.

The three-time Masters champion made the decision to play in Houston after two days of "light practice" at Augusta National, where he said his side "felt sore as opposed to hurting."

Mickelson began play Thursday morning at the 10th tee at 7:50 a.m. with fellow former major winners Webb Simpson and Keegan Bradley

He was 2-under through nine holes at the time this story was posted.

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