JD Martinez is one of the older possibilities for the Mariners to consider in free agency (he is 36 years old). However, he could provide a veteran presence, and also be a solid middle of the order bat. Martinez hit .271, with an .893 OPS, 103 RBI, and 33 HR in a stacked LA Dodgers lineup. He played in just 113 games, but he made the most of those appearances. Martinez would likely be a short term option for the Mariners given his age, but given his breadth of experience he could be just what the M's are looking for.
If the Mariners sign JD Martinez, his numbers at T-Mobile Park stand out. For his career, JD Martinez has a .328 batting average, .970 OPS, 9 HR, and 25 RBI in 33 games at T-Mobile Park. The only significant question is his inability to play the outfield. Jerry Dipoto has stressed he wants to sign a DH who can also play in the outfield as a platoon player to protect left-handed outfielders such as Dominic Canzone. The Mariners could always look past the fielding issue with Martinez. They could decide to give a younger outfielder such as Jonatan Clase, a chance to play in the big leagues if they sign Martinez.