Manager Tony La Russa said the plan is to not rush Berkman back to action, but the slugger was available to pinch-hit against the Cubs on Saturday.
"We don't want to get him back and have him aggravate it," La Russa said. "We want him to [come back and] stay."
La Russa said he was leaning toward playing Berkman on Sunday in the series-finale against the Cubs but would hold off if the slugger needed more treatment.
Berkman, though, was confident he would be back on the field on Sunday.
"It feels good, a lot better today," Berkman said on Saturday. "I feel like I will be able to play [on Sunday], no problem."
Berkman received a cortisone shot in his shoulder on Wednesday and has not played since Tuesday, when he was lifted from the game after two at-bats with discomfort in his shoulder.
The six-time All-Star first felt something amiss during his final swing of Sunday's loss to Pittsburgh, and the problem resurfaced at the plate on Tuesday against Houston.
He took batting practice on Saturday and reported no major issues with the shoulder.
"I don't think you can expect to feel completely normal, or pain free," Berkman said. "But compared to where it was, it's a lot better."
Skip Schumaker started in right field on Saturday in Berkman's stead.
Berkman leads the National League with 27 home runs and is hitting .286 with a team-high 69 RBIs in 92 games this season.