Liddi, 24, batted .267 (55x206) with 8 doubles, 2 triples, 9 home runs and 37 RBI in 50 games for the Tacoma Rainiers. He appeared mainly at third base for the Rainiers (42 games, 41 starts), but also played first base (7 games/starts) and designated hitter (2 games/starts).
Liddi appeared with the Mariners in each of the last two seasons, combining to bat .224 (35x156) with 6 home runs and 16 RBI in 53 games. He native of Sanremo, Italy was originally signed by Seattle as an International Free Agent on Sept. 9, 2005 and was the first Italian-born and developed player to play Major League Baseball when he debuted in 2011.
Maurer, 22, made 10 starts for the Mariners going 2-7 with a 6.93 ERA (38 ER, 49.1 IP). He started the Mariners last game Tuesday vs. the San Diego Padres, allowing 9 hits and 6 runs in 5.2 innings.
The Mariners will make an additional roster move prior to Sunday's game at Minnesota, the spot where Maurer was scheduled to pitch in the rotation.