The New York Mets have placed left-hander Johan Santana on the 15-day disabled list with a sprained right ankle.

Santana suffered the ankle injury covering first base in his final-half start on July 6. After twisting the ankle, the Cubs' Reed Johnson stepped on him, worsening the situation.

Santana's 2012 ERA stands at 3.98, which is worse than the NL average of 3.96. Including the start on July 6 in which he injured himself, he's given up 19 runs over his last 12.2 innings pitched.

The Mets believe he is fatigued and could use the rest.

As for who will replace Santana in the Mets' rotation, which was already thinned out by the loss of Dillon Gee, right-handed prospect Matt Harvey seems like a leading candidate.

The New York Mets are 4.5 games out of one of the NL wildcard spots, and though R.A. Dickey is having the greatest season of his career, the lack of depth in the starting rotation and in the bullpen may be the ultimate undoing of the Mets in 2012.

With the Mets slowly falling out of contention in the National League, this could be the kind of loss that kills any remaining hope for the New York faithful. While that is a hard pill to swallow, it's better for Santana's long-term success.