Giants lose at Miami on Justin Bour’s 3-run HR in 9th

MIAMI — Rarely can a team blow a two-run lead in the ninth, lose on a three-run homer off the closer and declare that the evening could have been much worse.

The Giants could say just that after Wednesday night’s 6-5 loss to the Marlins, on Justin Bour’s three-run blast off Santiago Casilla.

[...] he was alert and seemed fine after taking a foul shot to the mask in the second inning and leaving in the fifth.

If Posey cannot play in the series finale Thursday, with the Giants trying to avoid a sweep against a team that had been gasping for wins, Andrew Susac will be the lone catcher available, with Joaquin Arias or Ehire Adrianza as the emergency backups.

Susac and mates took the field for the bottom of the ninth leading 5-3 after the Giants came from two runs down, grabbed a 4-3 lead in the sixth on Brandon Crawford’s career-high 11th home run (off Dan Haren) and added an insurance run.

Casilla did not get an out in an inning that doomed the Giants to their second loss this year after taking a lead into the ninth.

Susac called for a 1-0 curveball to Bour, but Casilla shook him off and decided to throw a sinker, normally his best pitch.

The rookie first baseman, who took Michael Morse’s job, lined it over the right-field fence near the Marlins’ bullpen to end the game.

The Giants had overcome a 3-1 deficit and scored the tying and go-ahead runs in the sixth, on a Matt Duffy double, Brandon Belt sacrifice fly and Crawford’s homer.