MIAMI -- San Diego Padres pitcher Nick Martinez left the World Baseball Classic on Saturday after he wasn't guaranteed to start for Team USA for the rest of the event.

United States manager Mark DeRosa said Martinez will return to Padres spring training to prepare for the start of the major league season.

"I didn't feel that was fair to us as a whole or to him to guarantee that, regardless of result," DeRosa said. "We're trying to win this thing, so I thought it was best for everyone -- and he agreed -- that he would go back and get ready for opening day with San Diego."

Lance Lynn will start for Team USA in Saturday's game against Venezuela with a spot in the WBC semifinals on the line.

DeRosa said he decided to go with Lynn because the Chicago White Sox pitcher "threw the ball the best" so far in the tournament.

Lynn picked up the win against Canada last Monday, striking out six and allowing just two hits and one run in five innings.

Martinez started Game 2 of pool play against Mexico and was the losing pitcher, allowing five hits and three runs with two strikeouts in 2 2/3 innings of the 11-5 defeat.