On Tuesday, general manager Sandy Alderson said he wanted to add some rotation depth as insurance in case Johan Santana isn’t ready to start the season.

He followed through on that today as the Mets signed veteran left-handed swingman Chuck James to a minor-league contract. James received an invitation to major-league camp.

James, 30, worked strictly out of the bullpen last season with Minnesota, but has spent most of his career as a starter. Last season he struggled during a brief stint with the Twins where he posted a 6.10 ERA in 10 1/3 innings pitched, but he did post some excellent numbers in the minors.

While pitching for Triple-A Rochester, James posted a 2.30 ERA and 1.21 WHIP in 38 appearances spanning 62 innings in which he struck out 67 batters.

James has been battling back from surgery to repair a torn labrum.

According to Anthony DiComo, James will battle Daniel Herrera and Robert Carson for a spot in the team’s Opening Day bullpen. Left-hander Tim Byrdak recently signed a guaranteed contract and is a lock to make the Opening Day roster, along with right-handers Frank Francisco, Jon Rauch and Ramon Ramirez.

I like this move. There’s nothing to lose and potentially a lot to gain here.