SF Giants’ rotation takes a blow as Robbie Ray lands on IL

MILWAUKEE — Already facing an uphill climb to the postseason, the Giants now will be without one-fifth of their rotation for almost half of their remaining schedule.

Robbie Ray was placed on the 15-day injured list Tuesday after an MRI revealed a strain in his left hamstring, the team announced. He won’t be eligible to return until September 10, at the earliest, and while he expressed optimism that it was mild, the team did not disclose the severity of the strain.

Manager Bob Melvin is expected to provide more details when he addresses reporters before the start of their series against the Brewers, including plans to cover Ray’s spot in the starting rotation. They should benefit from a pair of off days within the span of a minimum IL stay, but in the meantime they recalled right-hander Landen Roupp from Triple-A Sacramento to fill his roster spot.

Roupp, 25, has a 4.70 ERA in 15 appearances out of the Giants’ bullpen and past experience as a starter but hasn’t been stretched out past three innings this year. He had just been optioned Friday when the team called up Camilo Doval but was eligible because of Ray’s injury.

Making his seventh start back from a 16-month absence after undergoing Tommy John surgery, Ray winced and grabbed at his hamstring on the 62nd pitch of his outing Sunday in Seattle. He didn’t attempt to throw another pitch and told reporters afterward he hoped that would mitigate the severity of the injury.

The 32-year-old left-hander had a 4.70 ERA while striking out batters at the highest rate of his career — 12.6 per nine innings — but didn’t complete five innings in three of his seven starts, and his injury-shortened outing Sunday was the third straight game the Giants got four or fewer frames from their starting pitcher.

Their ace and the National League leader in innings pitched, Logan Webb, takes the ball to open their series in Milwaukee, and even with a couple of days off sandwiching their weekend set in Seattle, their bullpen would surely appreciate a breather.

Between the results of Ray’s MRI and on the out-of-town scoreboard, the Giants’ path forward only got more challenging while they rested.

They entered Tuesday with a season-low 2.6% chance of making the postseason, according to FanGraphs, after the Atlanta Braves won Monday, widening their advantage to 5½ games (six in the loss column).

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