The Phillies and Marlins have reached a trade that sends All-Star catcher J.T. Realmuto to Philadelphia for catcher Jorge Alfaro, pitching prospects Sixto Sanchez and Will Stewart, and an international bonus slot, the teams announced Thursday.

After months of negotiations with a half-dozen teams for the 27-year-old Realmuto, the Marlins finally dealt him to Philadelphia, which remains a likely destination for one of the two biggest free agents left on the market: Bryce Harper or Manny Machado.

"This is about us acquiring the best catcher in baseball," Phillies general manager Matt Klentak said, "and we're really excited about that."

Sanchez is the most well-regarded prospect in the deal, a 6-foot right-hander whose fastball sits in the high 90s and tops out over 100 mph. The 20-year-old missed a majority of the 2018 season with elbow inflammation. Alfaro, 25, is a power-hitting, cannon-armed catcher who will join a young group in Miami. Stewart, 21, excelled in Class A last season, going 8-1 with a 2.06 ERA in 20 starts.

"We did not have to trade J.T.," Marlins president of baseball operations Michael Hill said. "But our goal is to build a long-term sustainable championship organization."

Philadelphia outlasted pushes by the Cincinnati Reds, San Diego Padres, Atlanta Braves and Los Angeles Dodgers to deal for Realmuto. He is the Phillies' fourth big acquisition of the offseason, following the signings of outfielder Andrew McCutchen and reliever David Robertson, plus a trade for shortstop Jean Segura.

"We're talking about the best catcher in all of baseball, so of course he was popular," Hill said.

Regarded by many inside the game as the best catcher in baseball, Realmuto has two years before he hits free agency. He hit .277/.344/.480 in 2018 with the Marlins, who in the past two offseasons have traded him, the last two National League MVPs -- Giancarlo Stanton and Christian Yelich -- as well as outfielder Marcell Ozuna.

"We have heard outstanding things about J.T. and his work ethic and his makeup and his leadership and the type of teammate he is," Klentak said.

While the return on the deals for the outfielders last season remains questionable, Miami is hopeful Sanchez and Alfaro can blossom into stars. Sanchez especially has incredible upside, though the list of short, right-handed starters with huge velocity who have succeeded in the major leagues is not long.

"In Sanchez, we saw a front-of-the-rotation starter," Hill said. "Electric stuff -- a pitcher we think can develop and lead a championship rotation."

The Associated Press contributed to this report.