Miami has won four straight and 10 of its past 13 games, including a 6-2 win on Wednesday to set up the opportunity for the sweep.
"This is my fourth year here and I'm not gonna lie, this is probably the most fun I've ever had in the big leagues playing baseball," Miami center fielder Jazz Chisholm Jr. said. "I always try to have as much fun as I can, but this is a different level of fun with these guys in there."
The Marlins are also 11-3 in their past 14 road games, having won six straight outside of Miami, and they sit 13 games over .500 for the first time since 2009
Reinforcements have helped the team's recent success in Boston, as Chisholm and third baseman Jean Segura have just returned from injuries.
Chisholm, out since May 14 due to turf toe, went 3-for-4 with three RBIs in Tuesday's series opener in his first game back, then hit an eighth-inning home run on Wednesday.
Segura, sidelined for nearly two weeks because of a hamstring strain, homered on Tuesday in his return. He added a two-run single on Wednesday.
"They've had a lot of time off and probably watching the team doing really well without them and wanting to be part of this thing," Marlins manager Skip Schumaker said on Tuesday. "I think the pressure (was) a little bit off of them, too, because they don't have to come back feeling like they have to be the hero. Just (being) who they are is good enough for us.
The Marlins will finish the series with a second straight left-hander on the mound. Jesus Luzardo (6-5, 3.77 ERA) is set to oppose Boston for the first time
Luzardo, 25, leads the Miami staff with 103 strikeouts through 16 starts. He fanned nine batters -- his second-highest total of the season -- across seven shutout, two-hit innings on Sunday against the Pittsburgh Pirates, his eighth quality start.
The Red Sox, who are on a four-game skid and have a 2-12 home record against National League teams this season, will attempt to salvage the series finale
Alex Verdugo had a 13-game hitting streak snapped on Wednesday.
The emergence of Brayan Bello (5-4, 3.27 ERA) as a consistent starter has been a major bright spot of Boston's season to this point. The 24-year-old right-hander will attempt to continue his success on Thursday.
Bello has worked at least six innings in each of his past four starts and five of his past six, which includes back-to-back, seven-inning outings against the New York Yankees earlier this month.
In his most recent start, Bello worked 6 2/3 innings of one-run ball to beat the host Chicago White Sox on Friday.
"My goal is always (to) try to go deep into the game so I can help the bullpen, and that has been my mentality since I came up here," Bello said. "I'm trying to get quick outs. I'm not trying to strike out anybody, and that's been the key to go deep into the game."
Prior to Bello, the most recent Red Sox pitchers to post a sub-2.50 ERA in a 10-start span before turning 25 years old were Jon Lester, Aaron Sele, Roger Clemens and Dennis Eckersley
Bello's work ethic has been impressive.
"He's very hungry," Red Sox manager Alex Cora said. "He understands that he's good, but obviously there's a lot of work that we have to do for him to get to where we want to.
Bello will be making his first career appearance against Miami.
--Field Level Media