Blalock, 27, went 6-for-12 with Frisco, getting two hits in all three games. He had a pair of doubles and a walk and struck out just once.

Blalock will move to first because his shoulder can't handle the stress of playing third base anymore. He has twice tried to play the position this season and has twice landed on the DL as a result. While out in April and May, he started to learn the nuances of playing first base, and the original plan was for him to return to the club as a first baseman. But the arrival and hot start of rookie Chris Davis led to moving Blalock back to third.

Blalock played nine games at third in July before going back on the DL with a sore shoulder. After his shoulder acted up again while he was trying to rehab, the Rangers decided they would go back to having him play first and would move Davis to third. Davis played third in the minors last year.

The move could force third baseman Travis Metcalf out of the picture. There will be little playing time for Metcalf with Blalock and Davis on the active roster, and somebody will have to be shipped to the minors to make room for Blalock.