Johan Santana is becoming "less and less likely" to be ready for the team's opener against San Diego on April 1.

Santana was scheduled to throw batting practice Tuesday, but pitching coach Dan Warthen said Saturday that the session had been canceled.

Sandy Alderson said it will be 10 more days before Santana builds up enough arm strength to pitch in an exhibition game.

"We haven't ruled out opening day, although given when he might get on the mound, it becomes less and less likely," Alderson said. "But we haven't given up on that notion yet and we'll see where that takes us."