TAMPA, Fla. -- The injury that will keep New York Yankees first baseman Mark Teixeira out of the lineup until May at the earliest is not a wrist strain, as originally reported, but a partially torn tendon sheath that could potentially require season-ending surgery.

As of now, the Yankees are still expecting Teixeira to heal without needing an operation and to rejoin the club after about 8-10 weeks of healing time.

But Teixeira, who arrived at spring camp Sunday morning with his right wrist in a cast-like splint and will rehab there for the rest of the spring, raised the possibility that his absence could be longer than that.

"This is one of those things I can't come back too early,'' he said. "We saw last season when I tried to play too early [with a calf injury] what happened. If I try to play too early from this we could miss the whole season, and we don't want that. I don't know if it's the beginning of May, the end of May, the beginning of June, I don't know when it is but we got a whole bunch of season left and the time that really matters is the playoffs.''

Yankees general manager Brian Cashman was surprised to hear Teixeira say the injury was to the tendon sheath, a covering that keeps the wrist tendon in place, rather than to the tendon itself. He called Yankees team doctor Chris Ahmad, who told him the injury was a partially torn tendon sheath but a stable tendon, an injury that generally heals without surgery.

"Ahmad told me if he had a fully torn sheath, it's automatic surgery, and if he had a partially torn sheath with an unstable tendon, it's automatic surgery,'' Cashman said. "This is a best-case scenario injury, the only one that can heal without surgery.''