Daisuke Matsuzaka struck out the only batter he faced in the seventh inning as the New York Mets won 3-2 against the St. Louis Cardinals on Wednesday.

With the Mets up 3-1, Matsuzaka replaced Jonathon Niese with two outs and a runner on second, and fanned Mark Ellis on four pitches to get out of the inning. He wasn't involved in the decision.

Matsuzaka, who made his third appearance in his new role as a reliever, admitted working out of the pen has been more difficult than he imagined.

"Relief pitching is tough," Matsuzaka said. "I was just focused on keeping the baserunner from coming home."

"When you start, you can make adjustments along the way, but when you're relieving, you've got no room for error. It's really hard work."

Matsuzaka has clearly impressed manager Terry Collins, who said the right-hander could even start closing games.

The Mets have already gone through two closers this season, with Bobby Parnell having had Tommy John surgery and Jose Valverde losing the job to Kyle Farnsworth, who allowed a run on three hits to pick up his second save Wednesday.

"No question," former Orix Buffaloes skipper Collins told ESPN, when asked if he would try Matsuzaka in the ninth. "The adjustment he made at the end of last season, those walks went away."

"We know he wants to start. But he said, 'If you need me in the pen, I'll be ready.' "