Initially, Bartlett was expected back at the start of the second half, but the Rays opted to take the cautious route by giving him a few extra days off.
"[The knee] won't be totally healed until the season's over," Bartlett said. "But the more time I get, the better I will be. I figured the extra week will let me come back and play every day. And that's what I wanted to do. I didn't want to come back a week ago and play a week and have to have a day off because I'm still sore."
Zobrist, who has been filling in at shortstop in Bartlett's absence and went 2-for-3 with two RBIs in Wednesday's 4-3 win over the A's, became the corresponding roster move to make room for Bartlett.
"I've just got to keep working on things, because as you've seen, anything can happen, and I could be up here in a couple of days, you never know," Zobrist said.
Earlier in the week, Rays manager Joe Maddon said he was not sure if the club would need to go easy on Bartlett upon his return by not having him play every day. Maddon sounded different Wednesday.
"As of right now, just talking to [Bartlett], it might not be necessary," Maddon said. "He's feeling pretty good."
The Rays appear to be headed for inclement weather in Kansas City, which was also a concern for Maddon in regard to Bartlett.
"I'm looking at the weather map in Kansas City, and it's not a good weather map," Maddon said. "So we talked about the threat of a doubleheader. I don't know if that's true or not, but there's a threat that a game could be rained out."
If a game got rained out it could result in a doubleheader.
"The only concern I have is that J.B. would have to play two games," Maddon said. "But he's feeling pretty good right now. ... I would not rule him out [to play both games, though, if necessary]."