CHICAGO — Following a delay of more than 2 ½ hours, the Red Sox and White Sox were rained out at U.S. Cellular Field, leading to a day-night doubleheader today.

But the teams aren’t out of the woods — or the rain — yet. Weather forecasts for today call for heavy rain in the Chicago area from early afternoon until well after midnight, calling into question the ability to play both games today.

The teams are set to play a nationally televised game tomorrow afternoon at 2:55 CST, making it impossible to play a day-night doubleheader. There has been discussion of a single-admission doubleheader tomorrow, with the second game starting 20 minutes after Fox’s first game telecast.

Rules prohibit playing a day-night doubleheader Sunday since it’s a get-away day for the Red Sox, but the teams could attempt a single-admission doubleheader, then, too.

Finally, the teams share a common off-day on Sept. 24 when a game (or two) could be made up. The Sox would be returning from Tampa the day before, concluding their final road trip of the season,

‘We’re going into [today] knowing it’s going to be a long day — at best,” Red Sox manager Terry Francona said.

The Sox will have last night’s scheduled starter, Josh Beckett, pitch the first game here, with Curt Schilling pitching the night game as scheduled. Meanwhile, the White Sox will flip their starters, with last night’s pitcher, lefty Jon Danks, going tonight and tonight’s scheduled starter, righty Jon Garland, going in the afternoon game.

Lopez caught in Chicago loop

Javy Lopez took the circuitous route back from the minor leagues.

Lopez was in Buffalo yesterday when he was told to come to Chicago and replace Jon Lester on the Red Sox roster.

But tornadoes in the Chicago area prohibited Lopez’ plane from landing. It was diverted to Milwaukee, where it sat on the tarmac for 2 ½ hours. Finally, the plane took off for what should have been an 18-minute flight to Chicago.

That flight took more than an hour as the plane circled Chicago, waiting for permission to land. Lopez arrived at the ballpark at 8:45 Central Time, where, 45 minutes later, the game was rained out.

“Knowing I was going back to the big leagues,” said a smiling Lopez, “was the silver lining of spending seven hours on a plane.”

Pedroia’s a scratch

Dustin Pedroia was originally in the Red Sox’ lineup here last night before the rainout, but two hours before the scheduled start of the rain-delayed game, was scratched and replaced by Alex Cora at second base.

The point was made moot several hours later when rain postponed the game.

Pedroia was hit in the elbow by a pitch in the third inning Wednesday night at Tropicana Field and left the game.

The rookie infielder told Francona late Wednesday night that he was fine and could play last night, a point he made again yesterday at U.S. Cellular Field.

But Pedroia felt some pain trying to swing yesterday afternoon and was pulled from the lineup. He continued to get treatment on the elbow (ice and stimulation).

Cora will start the first game today against the lefty Danks, with Pedroia’s availability for the night game to be determined.

News regarding outfielder Eric Hinske was similarly cautious. Hinske came out of Wednesday’s game with cramping in his right calf.

“He woke up pretty sore,” said Francona. “Hopefully, it’s nothing more than a day or two. The good thing is that it’s not a pull or strain.”

The Red Sox signed veteran shortstop Royce Clayton to a minor-league deal. Clayton began the season with Toronto, before being designated for assignment earlier this month. It’s likely that Clayton will get a September call-up when the rosters expand, since he can provide the Sox with an experienced middle infielder to back up Pedroia, Cora and Julio Lugo.

Veteran Joe McEwing, according to several scouts, has not shown much range at the position and wasn’t under consideration for a callup. Clayton is set to join the Pawsox in Buffalo today.

In 69 games with the Blue Jays, Clayton hit .254 with one homer and 12 RBI. He’s a career .258 hitter, who played 2,100 games with the Giants, Cardinals, Rangers, White Sox, Brewers, Rockies, Diamondbacks, Nationals, Reds and Blue Jays.

Mirabelli on the mend

Backup catcher Doug Mirabelli (right calf strain) continues to make progress in his rehab.

“He had a good day [Wednesday],” said Francona. “There was no swelling. He’s doing pretty well.”

Mirabelli is eligible to come off the disabled list when the Sox return from their current road trip. In the meantime, Kevin Cash is on hand as the number-two catcher and knuckleballer Tim Wakefield’s designated receiver.

smcadam@projo.com