FLEXEN FOR THE FUTURE

Chris Flexen will make his fourth major league start Sunday and it’s important for the 23-year-old to build off his last start. Flexen allowed three runs on four hits in 5.2 innings work as the Mets beat the Rangers 5-4 at Citi Field.

“It’s all about command. In his first starts it was a lot of deep counts. Then, when he would miss, he’d miss over the plate. I thought he had his best secondary pitches of the times he’s pitched up here so far,” Mets manager Terry Collins said. “You need those in the big leagues. You need to be able to throw them when you are behind in count. These guys think you are throwing a fastball and they attack it, they hit it hard. You gotta keep hitters off