Tim Byrdak will undergo knee surgery Tuesday

Mets relief pitcher Tim Byrdak was slated to be the only left-hander in the bullpen, but he's going to have knee surgery Tuesday and miss the start of the regular season.

The Mets bullpen suffered a big blow Monday morning. Tim Byrdak was slated to be the lone left-hander in the bullpen this season, but he has suffered torn meniscus in his left knee and will undergo surgery, general manager Sandy Alderson told reporters Monday.

That procedure will take place Tuesday in New York and will sideline Byrdak into the regular season. According to Alderson, Byrdak is down for six weeks (NJ.com via Twitter).

With him sidelined, the Mets are in a bit of a bind in the bullpen. Three other lefties were in major-league camp entering Monday: Robert Carson, Chuck James and Garrett Olson. Alderson said Monday that left-handed reliever Josh Edgin has also been moved into big-league camp (NJ.com via Twitter). So at least one of them needs to make the big-league club and replace Byrdak until he's ready to return.

Byrdak, 38, had a 3.82 ERA, 1.41 WHIP and 47 strikeouts last season in 37 2/3 innings.