Navarro, 25, batted .279/.366/.491 with nine home runs and 35 RBI in 66 games with Triple-A Indianapolis and .160/.232/.220 with one home run and four RBI in 29 games for the Pirates last season. He is a career .279/.350/.437 hitter in 536 games over seven minor league seasons.
Medina, 19, went 1-3 with a 4.14 ERA (50.0IP, 23ER) in 11 games with Gulf Coast (10 games) and Class-A Aberdeen (one game) last season.
To make room for Navarro on the 40-man roster, RHP STU POMERANZ has been designated for assignment. Pomeranz, 27, did not allow a run in 10 minor league outings (23.1IP) between Double-A Bowie and Triple-A Norfolk (five games with each) in 2012. He pitched to a 3.00 ERA (6.0IP, 2ER) in three games with the Orioles.
The club also agreed to terms on contracts for 2013 with INF ALEXI CASILLA, OF STEVE PEARCE and CA TAYLOR TEAGARDEN, thus avoiding arbitration.