Both players could take the field against the Miami Marlins on Saturday night as the Nationals try to win their 10th consecutive game started by the right-hander.Zimmermann (12-5, 2.83 ERA) improved to 6-0 with a 2.16 ERA in his last 10 starts after allowing six hits in 6 2/3 innings of a 3-0 win over the New York Mets on Sunday. It marked the first time the Nationals (89-64) won nine straight outings by one starter."Just got a good stretch going," Zimmermann said. "Nothing in particular sticks out."Washington's last loss with Zimmermann on the mound came 7-6 at Miami on July 28. He allowed two runs in seven innings and left with a 5-2 lead.Though Zimmermann has a 10.80 ERA without a decision in two home starts against the Marlins (74-79) this season, he's 1-0 with a 2.57 ERA in two at Miami.Washington, which remained 1 1/2 games ahead of the Los Angeles Dodgers for home-field advantage throughout the NL playoffs after Friday's 3-2 victory, hopes Zimmerman can be a key playoff contributor if healthy. The versatile former All-Star could return as early as Saturday from a strained hamstring that landed him on the disabled list July 23."It's nice, it's what great seasons are all about, kind of peaking at the right time, getting healthy at the right time," said reliever Tyler Clippard after the Nationals won for the 10th time in 13 games.Batting .387 with 17 RBIs in his last 17 games, Zimmerman progressed nicely enough during a recent rehab program to join the team at Marlins Park this weekend."The question would be whether he would play (Saturday) here, or whether he needs a day," manager Matt Williams told MLB's official website."He's sore right now, it's like spring training," Williams added. "I don't think it's hamstring sore, it's just general body soreness."Zimmerman, who missed almost two months with a broken thumb earlier this season, is batting .353 with four homers and seven RBIs in his last eight against the Marlins.Washington first saw Jarred Cosart (4-2, 2.05) when he allowed a solo homer to Jayson Werth, another run and struck out six in six innings while not factoring in the decision of a 4-3 loss with Houston on April 29.Since giving up four runs in 5 1/3 innings of a 5-2 loss to Cincinnati in his Miami debut Aug. 1, Cosart is 4-1 with a 1.52 ERA in seven outings.He allowed two runs in six innings while failing to earn a decision in a 6-5 victory over the Mets on Monday. The right-hander is 13-9 with a 3.67 ERA in 28 starts between Houston and Miami this year.Justin Bour hit his first career home run and had both RBIs on Friday as Miami lost for the 16th time in 26 games.Teammate Garrett Jones is 4 for 9 with a triple and a home run against Zimmermann in 2014.Washington's Adam LaRoche belted a two-run homer Friday for the only hit in his last 20 at-bats.