SAN FRANCISCO – Right-hander Joe Musgrove’s physical response to the bullpen session he threw Tuesday will determine whether he will start for the Pirates in Thursday’s series finale against the Giants.

Discomfort in Musgrove’s right foot forced him to miss a start last Friday vs. St. Louis. He has logged a personal Major League-high of 154 1/3 innings this year. Possessing a 9-12 record, he’s one victory shy of reaching double figures in wins for the first time in the Majors.

Musgrove hasn’t pitched since Aug. 31, when he yielded three runs and eight hits in six innings in an 11-4 triumph at Colorado. If he’s unable to pitch, right-hander Alex McRae likely would replace him. McRae filled in for Musgrove last Friday, surrendered two runs in five innings and received no decision in the Pirates’ 9-4 win.

Injury update

Center fielder Starling Marte (left wrist) was out of Pittsburgh’s lineup for the second game in a row. Marte pinch-ran in Monday’s ninth inning and scored one of the four runs that enabled the Pirates to surpass the Giants, 6-4. Pittsburgh manager Clint Hurdle would not project when Marte might be able to rejoin the lineup.

Marte has accumulated 46 RBIs in the seventh inning or later, most in the Major Leagues.