The News Tribune reported Chavez’s signing on Sunday while noting the club was close to a deal with Gutierrez.
Chavez, 36, is a 13-year veteran who split the last two seasons with the Mariners and Triple-A Tacoma. He batted .276 last year in 80 big-league games with two homers and 23 RBIs.
Gutierrez, 31, played five years for the Mariners from 2009-13 before missing all of last season because of severe gastrointestinal issues. That illness and other injuries limited him to 173 games from 2011-13.
The two additions swell the big-league camp roster to 57 players, including 17 non-roster invites.
Pitchers and catchers report for spring training on Feb. 20 at the Mariners’ year-round complex in Peoria, Ariz. The first full-squad workout is Feb. 25.