CINCINNATI -- Seeking to become competitive in the National League Central this year, the Reds have been aggressive and busy throughout the offseason. They could have one huge move left in them that would certainly provide added hope and expectations.

A source told MLB.com on Monday that Cincinnati is involved in talks for Marlins All-Star catcher J.T. Realmuto and that Reds president of baseball operations Dick Williams and general manager Nick Krall are being very proactive in their efforts.

It is not known exactly whom the Reds would send to Miami in exchange, but the cost is likely to be steep.

MLB Network insider Jon Heyman has reported that the Marlins have shown interest in the Reds' top four prospects -- Nick Senzel, Taylor Trammell, Hunter Greene and Jonathan India, who were all in the Top 100 overall rankings MLB Pipeline revealed on Saturday. MLB.com's Joe Frisaro reported that India is among the names in discussion and that Miami is also weighing the prospects being offered by other teams.

The Marlins would also need a catcher who is Major League ready or a near-ready catching prospect, and at least another elite prospect. Tucker Barnhart, a Gold Glove winner in 2017, has three years and a club option remaining on his four-year contract with Cincinnati and will earn $2.5 million in '19.

Realmuto, who will turn 28 in March, has become one of top catchers in the big leagues. Although he is on par defensively with Barnhart, Realmuto would be an upgrade offensively after he batted .277/.340/.484 with 21 home runs and 74 RBIs last season. He was valued at 4.3 wins above replacement, according to Baseball-Reference.

Barnhart, 28, batted .248/.328/.372 with 10 homers and 46 RBIs and was valued at 0.9 WAR.

Besides the haul required to get Realmuto, the Reds will also have to weigh the fact that he has only two years of club control before he's eligible for free agency. Second-year eligible for arbitration this winter, he already avoided the process by signing a one-year, $5.9 million contract.

Williams and Krall have overhauled the Reds' rotation already with the trades for Sonny Gray, Tanner Roark and Alex Wood, and outfielders Yasiel Puig and Matt Kemp also have been added. Williams and Krall have maintained the club was not finished trying to improve. Catcher wasn't viewed as a need because of Barnhart, however, as the team is still seeking a center fielder and a bullpen arm.

The Reds are also not alone in the pursuit of Realmuto. The Padres and Dodgers are believed to be top contenders, with the Braves also in the mix.