"It feels a lot better today," Middlebrooks said before the Padres opened a four-game series against the Cardinals. "I'd like to think I'll be available today and play tomorrow. We'll give it one more day and I'll be good to go."
Middlebrooks left Sunday's 6-4 loss to the D-backs in the seventh inning after he slipped on a weighted ball in the on-deck circle in front of the visiting dugout at Petco Park.
"It was a freak thing," Middlebrooks said. "… But I'm surprised it doesn't happen more often."
Middlebrooks slipped just as he and catcher Derek Norris converged on a Cliff Pennington pop-up in foul territory. He left the game and was replaced by Yangervis Solarte.
Solarte got the start at third base on Thursday.
"It looked much better today and he felt much better today," said Padres interim manager Pat Murphy. "He's pretty close."
Middlebrooks was able to pinch-hit in Tuesday's loss to the Mariners, though that's been his lone at-bat since the injury. He considered himself lucky to not have been hurt more.
"I feel like we dodged a bullet with it," he said.
Middlebrooks is hitting .221 this season with nine home runs and 28 RBIs.
• Relief pitcher Dale Thayer, on the disabled list since June 17 with a right shoulder strain, played catch before Friday's game. Murphy said Thayer will likely make a MiLB appearance this weekend, likely with the Padres' Double-A affiliate.
• Pitcher Brandon Morrow, who has been on the disabled list since May 3 with right shoulder inflammation, threw a 30-pitch bullpen session on Wednesday and will throw another bullpen on Saturday before the Padres face the Cardinals.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.