Shortstop Orlando Cabrera came down on his former teammate's hand while making the throw to first to complete the double play on Casey Kotchman's grounder to first.
"I hit him," Willits said, a bandage covering the finger, "and he came right down on it. The cut's on the top knuckle by the nail. It's about the length of a cleat."
Willits said he didn't know how severe the injury is. Manager Mike Scioscia said X-rays would be taken and Willits would be evaluated Sunday.
"There's a possibility he'll go on the DL," Scioscia said. "We'll know more when we see how it responds."
Willits, who had recovered from a left wrist injury sustained while he was playing for Triple-A Salt Lake, is batting .269 in limited duty. A versatile switch-hitter with speed, Willits was fifth in the 2007 American League Rookie of the Year balloting after helping drive the Angels to the AL West title.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.