Giants manager Bruce Bochy said Lollis understood the move, which balances the Giants' bench and pitchers after starter Chris Heston was optioned to clear space for Byrd.
"These players know," Bochy said. "They have a good idea."
Lollis was called up for a brief stint July 3 after the Giants designated now-Pirates first baseman Travis Ishikawa for assignment. After going 0-for-5 in two games, he was optioned to the Minors on July 7 when Hunter Pence was activated from the 15-day DL.
He was recalled Aug. 13 when Aoki was placed on the seven-day concussion DL. In his second stint with the Giants, Lollis made three appearances (two starts) and had two hits in seven at-bats.
His hitting in Triple-A this season has been noteworthy. With Sacramento, Lollis owned a .333 batting average (81-for-243) with four home runs, 18 doubles and 29 RBIs.
John McGonigal is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.