MIAMI -- The Miami Marlins may have a closer controversy brewing ... or maybe it is just a good problem to have.

The Marlins, fresh off a road sweep of the Pittsburgh Pirates, open a three-game series against the 2015 World Series champions, the Kansas City Royals, on Tuesday.

Kansas City (64-60) is even hotter than Miami, having won eight consecutive games -- the majors' longest active streak. Miami (65-59) has won three in a row. Still, neither team would be in the playoffs as the race currently stands.

The Marlins have been coping with a power void caused by injuries to right fielder Giancarlo Stanton and first baseman Justin Bour, who have combined to hit 40 homers in 171 games this season.

It is dubious whether either slugger will return this year.

In the meantime, both of Miami's left-handed starting pitchers -- Adam Conley and Wei-Yin Chen -- are on the disabled list.

The bullpen issue surfaced Sunday, when All-Star closer A.J. Ramos returned from the disabled list -- but not in his former role.

Fernando Rodney, who also made the All-Star Game this year on the strength of his work with the San Diego Padres, closed all three games in the Pirates series.

Ramos pitched the eighth inning Sunday, which left Marlins manager Don Mattingly to do some explaining.

"A.J. and I have talked," Mattingly said. "We're going to do what is best for the team."

The Marlins, trying to chase down the St. Louis Cardinals for the second and final NL wild-card berth, are just hoping that either Rodney or Ramos is in position to save Tuesday's game.

Miami will send right-hander Andrew Cashner (4-9, 4.92 ERA) to the mound for the series opener. Since being acquired from the Padres on July 31 in a package that included Miami's top hitting prospect, Josh Naylor, being sent to San Diego, Cashner has gone 0-2 with a 5.48 ERA in four starts.

His numbers are even worse in his past three starts: a 7.04 ERA. Cashner also has nine walks and just six strikeouts in his past two starts.

To get his first win with the Marlins, Cashner will have to cool off a red-hot Kansas City team and defeat right-hander Yordano Ventura (8-9, 4.46 ERA). The Royals have won each of Ventura's past four starts, and he has a 2.52 ERA during that span.

Royals left-hander Danny Duffy expects another quality outing from Ventura.

"Our rotation has been unbelievable," Duffy said Sunday. "Our bullpen is back, doing what we're known to do. The team's been doing great. We just have to keep that up."

Indeed, Kansas City has won five straight series and 13 out of 15 games. And after the series at Marlins Park, 20 of the Royals' final 35 games are at home.

Other story lines to watch:

--Marlins executive Michael Hill said Chen (left elbow) may not be back until late September. Hill said Conley (left hand) could be back sooner.

--The Marlins are rotating three players at first base -- Derek Dietrich, Xavier Scruggs and Chris Johnson. The team is also reportedly looking to make a trade to acquire outfielder Jeff Francoeur from the Atlanta Braves. Francoeur would be used as a backup and a pinch hitter.

--This will be the first series between Miami and Kansas City since the Marlins took two out of three from the Royals three years ago.