No matter how quickly the right shoulder of Alexi Ogando heals the fifth spot in the Texas Rangers’ rotation will remain an uncertainty the rest of the season.

Travis Blackley got the first crack Tuesday at replacing Ogando who has hit the disabled list for a third time and the left-hander kept the game close against his former team the Houston Astros.

Being within striking distance is the primary task for any starter who pitches for a team that features Adrian Beltre in its lineup.

Beltre swatted a two-run go-ahead homer in the sixth inning and four relievers delivered five scoreless innings as the Rangers won 4-2 and beat the Astros for the seventh straight time.

The victory ensured that the Rangers would keep at least a half-game lead in the American League West and moved them to 20 games over .500 (73-53) for the first time this season. Only two other teams in club history (1999 2012) have had a better record after 126 games.

Beltre meanwhile continues a torrid pace that included him being named the AL’s top player in July. At least one teammate believes that Beltre is deserving of a bigger honor.

“He’s having an MVP-caliber season” second baseman Ian Kinsler said. “I don’t know what else to say. He’s one of the best players in the league for one of the best teams in the league and he does it night in and night out.”

Beltre also doubled and scored the Rangers’ first run in the second inning to give him 17 straight games reaching base and hits in 17 of the past 21. The homer his team-leading 10th go-ahead shot left Beltre with multiple hits in 13 of the past 21 games.

He is batting .434 (33 for 76) the past 21 games and .383 since July 1 with 12 homers and 36 of his team-leading 78 RBIs.

“This is what I’m supposed to be doing right?” said Beltre whose .326 average is third in the league behind Miguel Cabrera and Mike Trout. “I’ve been lucky lately. I’ve been finding some holes.”

Blackley didn’t pitch long enough to qualify for the win which went to Neal Cotts (5-2) but he pitched well enough in his Rangers debut to be considered for the start when the No. 5 spot comes up again next week.

He threw 66 pitches and the only damage against him was a two-run homer by Matt Dominguez in the second inning.

“I felt I could’ve kept going” said Blackley who made his first start of the season. “It was solid. I made the one bad pitch there to a dangerous guy and paid the price. I seemed to find my groove in the third and fourth and I was pretty happy with it.”