Greene has been playing third base instead of his usual shortstop, during a rehab assignment he began last week. He's been on the disabled list, dealing with social anxiety problems, and was 6 for 15 with two doubles and two RBIs at Triple-A Memphis.
Manager Tony La Russa says switching positions could lessen the pressure on Greene, who played third base in college although not in the major leagues. Plus, the team still needs a fill-in for injured third baseman Troy Glaus.
"I just think he feels like he hasn't felt quite right, and third base is less responsibility," La Russa said. "That way you have one less thing to worry about. It's an option."
Khalil Greene, acquired in the offseason from San Diego, is hitting .200.
"We do have a couple of guys like Tyler and Brendan doing a good job at short," La Russa said. "So we're not forced to force Khalil."
Khalil Greene batted .213 last year with 10 homers and 35 RBIs, a big dropoff after he had 27 homers and 97 RBIs in 2007. He was sidelined for the remainder of the season after breaking his left hand when he punched a dugout wall in frustration in late July.