PITTSBURGH, Pa. - A.J. Burnett didn't get good news Monday after having an MRI on his ailing elbow. Yet the Pittsburgh right-hander knew it could have been worse.

Burnett was diagnosed with a strained flexor tendon, rather than a torn ligament.

"I'm going to do everything I can to make it back," the 38-year-old Burnett said.

Burnett also reiterated that he will retire at the end of the season.

Hours later, the scheduled game between the Pirates and Chicago Cubs was postponed after two rain delays totalling almost 3 1/2 hours.

No makeup date was announced.

The game was called at midnight with the score tied at 1 in the middle of the fourth inning. There was a delay of over 2 hours in the bottom of the second, then was rained out after a wait of 1 hour, 20 minutes.

Doctors told Burnett to rest four weeks before he starts throwing again. But he says that is subject to change.

Burnett was put on the 15-day disabled list Friday, day after giving up eight runs in 4 1-3 innings in a loss at Cincinnati.

Burnett has gone 1-2 with a 10.13 ERA in three starts since the All-Star break, allowing at least five runs in each outing. That came following a first half in which he went 7-3 with a 2.11 ERA in 18 starts and was selected to the All-Star game for the first time in his 17-year career

Burnett believes the support he is receiving from his teammates and fans will help spur his recovery.

"Social media has been off the hook," he said. "It's really humbling to know everybody is there and has your back."

Cubs rookie third baseman Kris Bryant was back in the lineup, a day after leaving a win at Milwaukee when he felt woozy following a headfirst slide into second base.

Bryant passed all of the necessary concussions tests Monday. On Sunday, Bryant's head struck Brewers shortstop Jean Segura's leg when he slid into second base in the fifth inning.

"I feel a little bit better," Bryant said. "I only have one head. I only have one life. There's nothing really to joke about with that, so we're taking it really serious."

Bryant is hitting .246 with 14 home runs and 61 RBIs in 95 games.

Both teams scored in the third.

Anthony Rizzo hit an RBI single for the Cubs. Michael Morse, who joined the Pirates earlier in the day, and Gregory Polanco doubled for Pittsburgh's run.

Starting pitchers Jon Lester of the Cubs and Francisco Liriano were taken out following the first delay.

TRAINER'S ROOM

Cubs: C Miguel Montero (sprained left thumb) is expected to be activated from the disabled list sometime during a four-game series against San Francisco that starts Thursday. He is 1 for 7 in two games on a rehab assignment with Double-A Tennessee.

ROSTER MOVES

Cubs: OF Matt Szczur was recalled from Triple-A Iowa to give Chicago a full complement of five players on the bench while LHP Clayton Richard was designated for assignment. RHP Dan Haren will take Richard's spot in the rotation Wednesday night against the Pirates after being acquired last Friday from Miami in a trade.

Pirates: Morse started at first base, three days after being acquired for the Los Angeles Dodgers in a trade. OF Jaff Decker was optioned to Triple-A Indianapolis.

UP NEXT

LHP J.A. Happ (4-6, 4.64) will make his first start for the Pirates on Tuesday night after being acquired last Friday from Seattle in a trade. Cubs RHP Jake Arrieta (11-6, 2.62) is 5-1 with a 1.53 ERA in his last eight starts.