Chase Utley began his minor league rehab assignment with Double-A Reading on Wednesday night. He'll likely rejoin the Phillies this weekend.

Utley wasn't the only big bat that arrived in Reading on Wednesday. The Phillies promoted third baseman Maikel Franco to Reading after he finished a torrid 65-game stretch at Class A Clearwater.

The 20-year-old Franco, a righthanded hitter, is arguably the best hitting prospect in the Phillies farm system. He hit .299 with a .925 OPS and 16 home runs this season at Clearwater.

Franco's home run on Tuesday night was his fifth in his last nine games. Franco, who also wields a plus glove at third, was leading the Florida State League in doubles (23) and was tied for the league lead in home runs at the time of his promotion.

Franco is expected to make his first start with the Reading Fightin' Phils on Thursday night at FirstEnergy Stadium.

The Dominican-born Franco, who turns 21 in August, was signed as an undrafted free agent in 2010.