The Giants announced Monday that they’ve signed catcher Curt Casali to a one-year, $1.5 million deal, adding a veteran backstop who will become the frontrunner to back up Buster Posey in 2021.

To clear a spot on the 40-man roster, the Giants sold the contractual rights of left-hander Andrew Suárez to the LG Twins of the Korea Baseball Organization.

Casali, 32, batted .260/.345/.440 with 18 home runs and 56 RBIs in 167 games over three seasons with the Reds, who non-tendered him in December. A 10th-round Draft pick of the Tigers in 2011, Casali has posted a .728 OPS over seven Major League seasons with the Rays and Reds.

Even with Posey expected to return this year after sitting out the 2020 campaign and top prospect Joey Bart on their 40-man roster, the Giants had expressed a desire to add more experience behind the plate this offseason. The addition of Casali is the latest indication that the Giants are leaning toward starting Bart in the Minors this season to give him more time to develop.

Bart, 24, took over as the Giants’ starting catcher after being promoted to the Majors in August, but he struggled to a .609 OPS and 41 strikeouts over 103 at-bats in 2020. Casali will be eligible to earn an additional $500,000 if he makes the Giants’ Opening Day roster this year. If he doesn’t, he can still earn up to $500,000 in bonuses for days spent on the active roster.

The Giants now have four catchers on their 40-man roster: Posey, Casali, Bart and Chadwick Tromp, who signed a Major League deal with the club after being non-tendered in December. Bart and Tromp have Minor League options, giving the Giants depth and flexibility as they head into the 2021 season.

Casali has ties to several current Giants, as he’s a close friend of outfielder Mike Yastrzemski, his former college teammate at Vanderbilt. Casali also caught right-handers Kevin Gausman and Anthony DeSclafani in Cincinnati.

Suárez, 28, was a second-round pick of the Giants in 2015 and logged a 4.66 ERA over parts of three seasons in the Majors.