Williamson called up to help fill in for Pagan

Outfielder is Giants' No. 7-ranked prospect; Okert sent to Sacramento

Williamson called up to help fill in for Pagan

CINCINNATI -- Given the possibility that left fielder Angel Pagan and second baseman Joe Panik will rejoin the lineup in a week or less, the Giants felt no need to be excessive Monday in seeking position-player reinforcements from the Minors.

Pagan underwent an MRI examination, which revealed a Grade 1 strain of his left hamstring that will sideline him for at least four or five days. That echoed the diagnosis of the club's medical and athletic training staffs, Giants manager Bruce Bochy said.

Panik, recovering steadily from a strained right groin, was available to pinch-hit Monday as the Giants opened a three-game series against the Cincinnati Reds. Bochy acknowledged he would have to employ a pinch-runner if Panik were to reach base.

Bochy added Panik could return to the lineup as early as Wednesday. More likely, Panik's comeback will occur Thursday when the Giants begin a four-game home series against Colorado.

To compensate for Pagan's absence, the Giants recalled outfielder Mac Williamson from Triple-A Sacramento and optioned left-hander Steven Okert to Sacramento.

Williamson, the organization's No. 7 prospect according to MLBPipeline.com, returned to the big club after going 0-for-3 in a brief callup earlier this season. This time, the right-handed-batting Williamson probably will platoon with left-handed-hitting Gregor Blanco in left field. In fact, Williamson started Monday against Reds lefty Brandon Finnegan.

Williamson, 25, was hitting .355/.382/.629 with four home runs and 18 RBIs in 15 games at Triple-A. Okert had a 6.35 ERA in five appearances for the Giants.

Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.