Thursday afternoon got off to a rocky start for Mets’ southpaw and fifth starter probable Jason Vargas, who surrendered a home run to Cardinals’ Matt Carpenter on just the second pitch of the game.

However, Vargas rebounded to set the next three batters down in a row, including punch outs to Dexter Fowler and Jose Martinez.

In the second inning, Vargas yielded a walk to Tyler O’Neill, but again set the next three batters down in a row, topped off by a strikeout of Francisco Pena to end the day.

Vargas, 36, was all but anointed the fifth starter a couple weeks ago by Mets’ manager Mickey Callaway, all but ruling out the possibility of New York bringing in an external arm like Gio Gonzalez.

The California native who signed a two-year deal with the Mets around this time in 2018, will look to turn it around after a rough season last year.

Vargas did rebound and pitch better down the stretch, but ended the year with a 7-9 record, 5.77 ERA, 5.02 FIP and a 1.413 WHIP in 20 games started.