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(SportsNetwork.com) - It's a long way from a spring training roster battle to a double-digit win season.

Still, that's precisely the scenario Tanner Roark will continue on Wednesday afternoon when he and the Washington Nationals visit Marlins Park for the finale of a three-game series with the Miami Marlins.

Roark was 7-1 with a 1.51 earned run average in 14 outings -- five starts, nine bullpen calls -- after reaching the big leagues as a rookie last season. He arrived this spring with a chance to land a full-time spot in the Washington rotation and has blossomed, picking up his 10th victory of the season with a 4-1 defeat of the Cincinnati Reds on Friday.

He gave up a run in seven innings of that win and has allowed two or fewer runs in eight of his last 10 starts. His 10 wins equal Doug Fister's for the team lead.

"I took the opportunity and tried to run away with it," Roark said. "It's been a good ride so far."

Though he's flanked by well-known starters Stephen Strasburg, Gio Gonzalez and Jordan Zimmermann, Roark has the best earned run average (2.82) in the rotation, helping Washington to a National League-best team mark of 3.11.

"We have the big guns and the big names, but you have to give (Roark) a lot of credit being in the back of the rotation and doing what he has done," outfielder Denard Span said.

He's split two decisions in three starts against the Marlins while compiling a 2.79 ERA.

Miami's Brad Hand came to spring training in a similar spot to Roark's, but was ripped for eight runs in 6 1/3 innings in a pair of April starts before a demotion to the bullpen. Twelve relief outings and a stint on the disabled list followed before he returned and has since made five starts, winning two of three decisions and posting a 2.43 ERA.

In his most recent outing, on Friday against Houston, he allowed three hits in 7 1/3 innings of a 2-0 win.

"I am still trying to go out every fifth day and solidify myself in this rotation," Hand said. "Nothing is going to be given. I'm going to have to prove it every fifth day."

Miami has won nine of 10 games to climb back to .500 for the first time since June 25. They were eight games below the break-even mark on July 19, but now trail the division-leading Nationals in the NL East by five games. Atlanta is only a half-game behind Washington.

"Guys are excited, there's a lot of confidence," manager Mike Redmond said.

Washington has lost four of six.

On Tuesday, Henderson Alvarez got the better of Strasburg, and Christian Yelich knocked in a crucial late run, as Miami topped Washington.

Alvarez (8-5) and Strasburg (7-9) both worked seven innings, but Alvarez held the visitors scoreless on three hits despite four walks and Strasburg let up one run on four hits. Steve Cishek loaded the bases with two away in the ninth, but emerged with his 27th save after fanning Anthony Rendon swinging.

Giancarlo Stanton drove in two runs for the Marlins.

Bryce Harper collected two of five hits for the Nationals.