An untraditional four-game series between the Boston Red Sox and Tampa Bay Ray is due to begin in an untraditional way on Saturday afternoon.

After the scheduled Friday night game was postponed due to persistent rain and thunderstorms, the American League East foes begin the series in Boston with a previously scheduled day-night doubleheader.

"A lot of baseball getting played," Rays manager Kevin Cash said entering the series.

The set is now slated to conclude with a rescheduled Monday afternoon game, taking away what had originally been a travel day for both teams.

Both teams' pitching plans for the doubleheader were not finalized entering what was set to be series opener, and Boston's plans were potentially complicated after losing left-hander Chris Sale to the 15-day injured list on Friday due to left shoulder inflammation.

"You cannot predict what happens before the doubleheader, but at the moment (we made the decision to schedule one) we felt really good," Boston manager Alex Cora said. "I'm not saying it feels worse now, but obviously the circumstances have changed. That's the beauty of 162 (games)."

After being set to start Friday, Garrett Whitlock (2-2, 5.14 ERA) will throw in the new series opener for the Red Sox, who have lost seven of their past 10 games.

It will be Whitlock's second start since being reinstated from the 15-day disabled list after recovering from right elbow ulnar neuritis. He allowed just one run on three hits in a five-inning victory at Arizona on May 27.

Whitlock started against the Rays on April 11, and he allowed five runs on eight hits over five innings in a 7-2 road loss. In seven career appearances (two starts) vs. Tampa Bay, he is 1-2 with a 4.76 ERA.

Boston's starting pitchers have allowed four or fewer earned runs in 12 of the past 14 games.

Cora had been excited about the rotation's makeup before Sale went down.

"He's really good, and this is where we're at," Cora said after Whitlock's latest start. "The three kids (Whitlock, Tanner Houck and Brayan Bello) and the two veterans (Sale and James Paxton) ... and there's two kids in the bullpen that are really good, too. Structure-wise, this feels good."

The Red Sox's starting pitcher for the second game was to be determined.

Tampa Bay is slated to go with Trevor Kelley (0-1, 4.91 ERA) as the Game 1 opener, while Taylor Glasnow (0-0, 6.23) is lined up for a start in the nightcap.

Glasnow pitched 4 1/3 innings of three-run ball against the Dodgers on May 27, which marked his return from a left oblique strain that sidelined him since February.

"I was glad to be back out there," Glasnow said. "Just to feel the emotions and, like, the adrenaline again was nice and kind of just got me back into that in-season routine."

As the 27th man added for the doubleheader, Cooper Criswell likely will work the bulk of the first game after Kelley.

The Rays went 17-12 in May and have seen 19 of their past 27 games decided by two runs or fewer. Jose Siri's two-run, eighth-inning homer was the difference on Wednesday in a 4-3 win over the Chicago Cubs, as Tampa Bay avoided being swept for the first time all season.

The Rays and Red Sox have not met since Tampa Bay swept a four-game home series from April 10-13. The Rays outscored the Red Sox 26-12 in that set.