The team made the move before Friday's game against the New York Yankees. Sogard is in the starting lineup for the game, batting eighth and playing shortstop.
Pennington is batting .197 with three home runs and 16 RBIs in 82 games. He has the lowest slugging percentage in the majors (.282) and the second lowest batting average and on-base percentage (.259).
Sogard is hitting .145 with two home runs and six RBIs in 22 games in three stints with Oakland this season.