Paxton underwent a microscopic lumbar discectomy to remove a peridiscal cyst Wednesday and will miss 3-to-4 months.
The back procedure will prevent Paxton from making his season debut until sometime in May or June. Injuries are unfortunately nothing new for the lefty, who's never reached the 30-start threshold in any of his seven major-league seasons. The injury opens up a temporary spot in the Yankees' rotation, with Jordan Montgomery looking like the favorite to win it.