It happened again Sunday afternoon. The Mets bullpen blew a lead in the seventh inning and surrendered two runs in the 10th for a 6-4 loss to the Astros. Of the Mets’ nine losses in August, the pen has taken the “L” in five of them.

Since the All-Star break, Mets relievers have posted a 5.79 ERA, which is nearly two runs higher than the 3.97 mark posted by all other NL relievers in 2008. The bullpen has taken the brunt of the criticism when the club has struggled in the late innings, but there’s plenty of blame to spread around.

The Mets, who went hitless in the final three innings Sunday, haven’t provided much run support for the pen. After the sixth inning, they are batting .241 -- the fourth-lowest mark in the National League -- and they’re slugging just .353. Only the Nationals (.341) have a lower slugging percentage from the seventh inning on.

New York has scored runs in bunches through the first six innings of games, but it’s been a different story over the next three frames.

Mets’ Runs Scored & Runs Allowed by Innings, 2008

. . . . . . . . . . . . . . . . . . . . . R. . . . . . . . . RA. . . . . . . .Diff
Innings 1-6. . . . . . . . . . . . . 488. . . . . . . . 370. . . . . . . .118
Innings 7-9. . . . . . . . . . . . . 147. . . . . . . . 196. . . . . . . .-49

Over the first six innings, the Mets have outscored opponents by a large margin for a run differential of 118. The only major league club with a better run differential through the sixth inning this season is the Cubs (122).

The late innings haven’t gone as well. Between the seventh and ninth innings of games, the Mets have been outscored 196-147. Only the Padres have scored fewer runs in those three innings, and the Mets’ -49 run differential is the worst in the major leagues.