Baron went 0-for-11 in four games for the Mariners in 2015 while spending much of that season with Triple-A Tacoma, where he hit .277/.316/.391 in 53 games. But he was back with Double-A Jackson last year, where he batted .280/.377/.358 with three home runs and 22 RBIs in 66 games.
Baron hit .234 with 26 home runs and 228 RBIs in 554 games over eight Minor League seasons since being selected with the 33rd overall pick in 2009 out of John A. Ferguson High School in Miami.
The Mariners currently have three catchers on their 40-man roster in Mike Zunino, Jesus Sucre and veteran Carlos Ruiz, who was acquired by trade from the Dodgers on Monday.
Additionally, general manager Jerry Dipoto said at the General Manager Meetings in Scottsdale, Ariz., on Tuesday that youngsters Tyler Marlette and Marcus Littlewood have advanced up the depth chart. Dipoto indicated the club would also likely pursue another experienced player to provide Triple-A depth.
Marlette, 23, hit .277/.335/.463 with 15 home runs and 59 RBIs in 98 games between Class A Advanced Bakersfield and Jackson, with 83 of those coming at Bakersfield. Marlette is currently playing in the Arizona Fall League, where he's hit .270 (10-for-37) with two homers and eight RBIs in 11 games.
"Marlette made a lot of progress this year in both the batter's box and behind the plate," Dipoto said. "Tyler has really created a niche for himself in the Fall League. He's stepped out and had a very good Fall League, particularly swinging the bat. And as you find out, the more you swing the bat, the more people think you can catch. He's done enough to promote himself."
Littlewood, 24, was drafted in the second round as a high school shortstop in 2010, but he was converted to catcher the following season. He hit .280/.380/.379 in 64 games this season, with 56 of those at Jackson and eight at Tacoma.
"He's had a nice and very quiet coming-out party as a catcher," Dipoto said.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.