Greene was injured after he struck out in the eighth inning of Wednesday night's 7-3 loss to the Arizona Diamondbacks. The shortstop is expected to be out six to eight weeks, possibly sidelining him for the rest of the season.

"I think it's a culmination of obviously frustrating moments, individually and team-wise," Greene said.

Greene fouled a ball off his shin before the strikeout. He punched the wall in the tunnel between the dugout and clubhouse with his non-throwing left hand.

"I'm not going into a ton of details, but I certainly regretted it immediately afterward," said Greene, who added he was in "extreme" pain after fouling the ball off his shin.

"I think that played a big factor and being frustrated. It was a pretty impulsive thing. It was a pretty quick thing, not too much thought behind it."

The Padres activated second baseman Tadahito Iguchi from the DL to take Greene's roster spot. Iguchi went on the DL on June 6 with a dislocated left shoulder.

Greene has struggled this year after enjoying his best season in the majors in 2007.

Greene is batting .213 with 10 home runs, 35 RBIs and a team-high 100 strikeouts in 389 at-bats. Last season, Greene was the club MVP when he batted .254 with career highs in homers (27), RBIs (97), runs (89), hits (155), doubles (44)and games played (153).

Luis Rodriguez was in the starting lineup at shortstop and batting eighth for San Diego's game against the San Francisco Giants on Friday night.