Speaking before the Heroes for Hope Gala on Monday evening -- the Jorge Posada Foundation's seventh annual event to raise awareness for craniosynostosis -- Cashman said long reliever Dan Giese, previously a starter in the Minors, or a hurler at Triple-A Scranton/Wilkes-Barre could be inserted into the rotation.
"I always try to go internal first, make sure the answer's not in front of us," Cashman said. "You keep your ears open at the same time. The trading deadline [of July 31] will be approaching here. Nothing's revealed itself at this moment in time."
Wang, who was hurt while running the bases in Sunday's 13-0 victory over the Astros in Houston, was examined on Monday in New York and has been diagnosed with a mid-foot sprain of the Lisfranc ligament of the right foot and a partial tear of the peroneal longus tendon of the right foot.
Wang will be on crutches and wear a protective boot for at least six weeks, the Yankees said.
According to that timetable, Wang would not be walking freely until almost early August, and Cashman said he would require four weeks of rehab duty to return his arm to Major League pitching condition, if he is to return at all during the 2008 season.
Cashman said he was going to talk to manager Joe Girardi at Monday evening's event to evaluate the team's options. Injured starters Phil Hughes and Ian Kennedy "aren't immediate choices," Cashman said.
Wang is 8-2 with a 4.07 ERA in 15 starts. He had given up just two runs and walked two batters during his last two starts.
"It's a blow," Cashman said, "but at the same time, the season's going to go on and our intention is to find a way to make the playoffs."
Wang's injury came in the final win of a three-game sweep, the fourth straight win for the Yankees, one that put them four games above .500 (37-33) for the first time this season.
"He's our best pitcher," Posada said. "The team is looking better and better, and it seems like something always happens when we get going, so this is just another challenge."
Willie Bans is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.