The Houston Astros and free-agent first baseman Christian Walker have agreed to a three-year, $60 million contract, sources confirmed to ESPN in multiple reports on Friday.

A medical review of the deal is still pending, a source told ESPN.

The signing of Walker most likely marks the end of Alex Bregman’s tenure in Houston, not to mention the Astros’ ill-fated attempts to lure Nolan Arenado away from the St. Louis Cardinals. Walker manning first base for the next three years means Isaac Paredes, the 25-year-old corner infielder recently acquired from the Chicago Cubs in the Kyle Tucker trade, is likely Bregman’s replacement at third Base will be.

Walker, 33, is widely considered one of the best defensive first basemen in the game and will also add some strength to the middle of the Astros’ lineup. Over the last three seasons with the Arizona Diamondbacks, he hit 95 homers and 281 RBIs and slashed .250/.332/.481 while amassing 10.8 FanGraphs wins above replacement, sixth-highest among first basemen.

First base had been a conundrum for the last three seasons in Houston that the high-priced Jose Abreu couldn’t solve. The Astros’ first basemen combined for an OPS of .651 last season, the fifth-lowest mark in the majors. Walker, a three-time Gold Glove Award winner, will provide a big boost at the position – especially as a right-handed hitter at Daikin Park, who has a short fence in left field.

The Astros still need help in their outfield after parting ways with Tucker a year before he is scheduled to become a free agent. And Bregman, the heart and soul of an Astros franchise that won two championships and appeared in seven straight American League Championship Series appearances since its first full season in the big leagues, must decide on a new destination.

The New York Yankees, who expressed interest in Walker this offseason, could be a landing spot for Bregman. The same applies to the Boston Red Sox, the Toronto Blue Jays or the Detroit Tigers, the latter being led by Bregman’s former manager AJ Hinch.

Astros general manager Dana Brown expressed optimism about bringing Bregman back throughout the offseason, but owner Jim Crane didn’t want to pay Bregman’s agent Scott Boras’ $200 million-plus asking price, sparking a first move for Arenado – before he used his no-go agreement. Trade clause to stay in St. Louis – and an agreement with Walker.

Walker declined the D-Backs’ qualifying offer earlier this month. With his signing, the Astros, a team that passed the luxury tax threshold last season, will forgo their second- and fifth-round picks in the upcoming draft as well as $1 million from their international spending pool. Once Bregman signs with another team, the Astros will get a fourth-round pick back, a development that now seems inevitable.

After losing to the Tigers in the wild-card round earlier this fall, the Astros’ longtime second baseman Jose Altuve spoke passionately about the importance of bringing Bregman back, saying, “We won’t be the same organization without him.”

In many ways, Walker’s signing marks a new chapter.