Pennington started at the keystone and went 2-for-4 in Sunday's victory over the Mariners.
Kaleb Cowart has emerged as the Angels' primary option at second base, but Pennington has picked up starts in two of the club's last three games, which have both come against southpaws. While both players are switch hitters, the former has struggled against lefties since being called up (4-for-20) while the latter has experiences success against that handedness this season (10-for-34), so a platoon situation at the keystone appears to be developing in Los Angeles.