Rays manager Joe Maddon noted that they wanted to take advantage of Thursday's off-day by giving Cobb an extra day of rest.
"We just thought it was prudent to give him one extra day," said Maddon, citing the fact that Cobb just came off the disabled list and is still building arm strength. "As long as there's no issues with the hitting [in the National League park], give him one extra day."
Maddon said that he talked to head athletic trainer Ron Porterfield and the pitcher about Cobb having to hit in an NL park.
"And neither of them feels as though there's a concern about swinging the bat," Maddon said. "... Which means Frenchy Bedard will start on Sunday [in Boston]."
Maddon said pushing Cobb back had nothing to do with him getting hit in the right leg during his start on Tuesday night against the Blue Jays. He said Cobb was on board with the move.
"Yeah, we had a good conversation," Maddon said. "Listen, it's all about keeping these guys healthy. If we don't keep our pitchers healthy, we're not going anywhere. And getting Cobber back [from the disabled list], finally, was such a boost to us. So now I think it's wise to take care of him.
"It's wise to take care of the bullpen. Again, to really get this thing down we have to be playing well in August and September. And in order to be playing well, you have to have your pitchers in good order. I'd rather take that moment right now and make sure he feels good."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.