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CINCINNATI -- Billy Hamilton and Dee Gordon first met as prospects in the Arizona Fall League on their way to the majors. The two speedsters, who are now vital batters at the top of their respective lineups, will have a reunion over the next four days in Cincinnati.

Hamilton's Reds host Gordon and the Miami Marlins for the first contest of a four-game series Monday night at Great American Ball Park. Left-hander Brandon Finnegan (7-8, 4.45 ERA) is due to pitch for the Reds, while right-hander David Phelps (5-6, 2.40) makes his third start for the Marlins since being moved into the rotation on Aug. 5.

Gordon and Hamilton didn't see each other when the Marlins swept a three-game series in Miami leading into the All-Star break. Gordon was serving an 80-game suspension for violating Major League Baseball's performance-enhancing drug program. In the 15 games since his return, Gordon is hitting .321 with seven stolen bases.

Hamilton leads the majors with 51 steals. He is the first player in the major leagues since Michael Bourn (2009-11) to have at least 50 stolen bases in three consecutive seasons, and he's the first Reds' player to accomplish the feat since Joe Morgan did it five straight seasons (1972-76).

Hamilton's giving himself the opportunities for those steals by getting on base at the highest rate in his career. His OBP is up to .318 after going 3-for-4 against Milwaukee on Sunday, marking his 22nd multi-hit game of the season.

Since the All-Star break, Hamilton is hitting .324 with 21 runs scored, five doubles, one triple, three RBIs, 29 steals and 12 walks. The Reds (48-68) have gone 16-11 in that span, winning seven of the nine series they've played.

"It's not as much the stolen bases as it is just how he affects everything else during the game," Brewers manager Craig Counsell told MLB.com about Hamilton. "Does he affect the pitcher? That's a big part of what we believe in with the running game, is, 'Can we affect the pitcher? Can we change his delivery? Can we affect his stuff to the hitter?'"

Miami (61-56) ended a three-game losing streak with a 5-4 win against the Chicago White Sox on Sunday. The Marlins are still 8 1/2 games behind Washington in the NL East but are in the thick of the NL wild card race, seeking the franchise's first playoff appearance since 2003.

Staying in the race with St. Louis, Pittsburgh and the New York Mets got tougher on Sunday when the team placed right fielder Giancarlo Stanton (groin) and pitcher Adam Conley (finger tendonitis) on the 15-day disabled list. An MRI revealed Stanton has a Grade 3 groin strain, putting the rest of the season in jeopardy for him.

"The best-case scenario is a six-week return," Marlins president of baseball operations Michael Hill said Sunday. "There's still an opportunity to get (Stanton) back before the end of the season, but it was a significant injury."

Stanton has 25 home runs, 70 RBIs and a slugging percentage of .497 this season.

"You're disappointed, but it's one of those things that you talk about as a ballclub from spring training forward," said Marlins manager Don Mattingly. "Nothing can get in our way. You've just got to move forward."

Phelps had 50 relief appearances before starting at Colorado on Aug. 5.

Finnegan will be making his 24th start of the season. In his last three starts, he's allowed 12 hits and just three runs in 18 innings. Finnegan has thrown 129 1/3 innings this season, and the Reds are keeping an eye on that total as the end of their season approaches.

"We could use off days and extra starters in September to give guys longer breaks and allow them to stay in the rotation," Reds manager Bryan Price said. "If we stayed with a five-man rotation, at some point the innings will accumulate where he would finish the season in the bullpen."