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The Oakland Athletics will try to pad their lead atop the American League West standings on Monday when they open a four-game series with the Texas Rangers at Rangers Ballpark in Arlington.

Oakland has taken advantage of Texas' recent woes and heads into this contest three games up on the Rangers, despite losing two of three to the Seattle Mariners over the weekend.

The Athletics avoided the sweep on Sunday, as Josh Reddick finished 4-for-5 with a homer and two RBI, while Josh Donaldson, Seth Smith and Brandon Moss all went deep in Oakland's 10-2 victory over the Mariners.

Bartolo Colon (9-2) continued his recent success and earned a victory in his sixth straight start after tossing seven innings of eight-hit, two-run ball. The righty has surrendered a combined five runs during the streak.

"That'd be awesome to see," said Reddick about Colon possibly starting the All-Star Game. "Especially toward the end of his career as he's coming down."

Getting the call for the A's on Monday will be righty Dan Straily, who is 4-2 with a 4.45 ERA. Straily won his third consecutive decision on Thursday on Wednesday against the New York Yankees, as he allowed two runs and three hits in 6 2/3 innings.

"He's on a roll," Oakland manager Bob Melvin said. "We're giving him more and more rope to face tough at-bats in the game. He's pitching with a lot of confidence right now, and he's been terrific."

Straily tossed seven scoreless innings to beat the Rangers earlier in the year and is 1-1 in three starts against them with a 2.50 ERA.

Texas, meanwhile, is in the midst of its first six-game losing streak since April, 2010. The Rangers have actually lost nine of 11 and have managed to score two runs or less in each of their last six games.

It's not just the offense, though. A Rangers starter has not earned a victory since May 31, a span of 15 games, the club's longest stretch since another 15- gamer from July 17 to Aug. 1, 1995.

"We're not the first team to lose six in a row and we probably won't be the last," Texas manager Ron Washington said. "We're tough enough to make it through this challenge."

Hoping to get the Rangers back on track Monday will be rookie right-hander Nick Tepesch, who has lost his last three decisions. Tepesch lost to Cleveland on Wednesday, as he surrendered five runs in five innings to fall to 3-6 on the year, while raising his ERA to 4.30.

He's allowed 11 runs in 12 innings of his last two starts, but the Rangers have plated two runs or less in four of his last five outings..

"I think in Tepesch's case, run support has been his biggest enemies," Washington said. "He gives up runs, but in his last four or five games, we haven't scored any for him."

Texas has split its six meetings with the A's this season.