In desperate need of a second left-hander in the bullpen to pair with Tim Byrdak, the Mets designated for assignment Vinny Rottino in the early morning hours and called up southpaw Justin Hampson.

Hampson, 32, was 5-4 with a 3.38 ERA in 79 appearances (one start) for the Rockies and Padres from 2006 to 2008.

This season, he was 4-2 with a 2.13 ERA and two saves in 28 appearances with Triple-A Buffalo. He did allow two runs in two innings -- including a solo homer to lefty hitting Matt Mangini -- Sunday night at Durham and suffered the loss. Overall, lefty batters are hitting .218 against Hampson this season, versus .233 for right-handers.

The Mets were stung by Robinson Cano's game-deciding homer Sunday night against Miguel Batista, which may not have been the matchup had Terry Collins had a second lefty at his disposal in the bullpen. The Mets did have left-hander Robert Carson briefly in the bullpen earlier this season, but Collins did not appear comfortable inserting the rookie in pivotal spots.

Rottino was DFA'd rather than optioned so that a 40-man roster spot could be opened for Hampson. Now Rottino must be exposed to waivers if the Mets want to send him to Buffalo. The move also restores the Mets' bullpen to seven relievers, after a weekend of playing with an extra bench player.