Mariners may be a dark horse candidate to trade with the Diamondbacks ahead of the deadline

The Luis Castillo deal firmly puts Seattle in the buyers category, can the Diamondbacks match up in a potential trade?

Last night, the Mariners made a splash in the trade market by trading three of their top five prospects to the Cincinnati Reds for Luis Castillo. The Mariners currently sit in the second Wild Card spot in the American League at 54-47 and intend to compete for a playoff spot thanks to a young and exciting core of position players complemented by a mix of high octane arms in their rotation and bullpen.

So how does this trade affect the Arizona Diamondbacks? The Diamondbacks are in a position where they may be looking to sell off older and less controllable talent and try to rebuild for the next two years. The Mariners could be an interesting trade partner if they’re looking to upgrade their lineup with a left-handed bat in David Peralta or pick up a left-handed relief option in Joe Mantiply.

Looking at Seattle’s production in both left field and the designated hitter spots, the Mariners rank 19th and 27th in wRC+ against righties. The Mariners are currently batting Jesse Winker and Carlos Santana at those spots, who sports a wRC+ of 98 and 92 respectively. Peralta sports a 121 wRC+ when he has the platoon advantage, which would be an upgrade for the Mariners. Trading for Peralta would also take Winker off the field for a better defender and either move him to the designated hitter spot or a 4th outfielder role off the bench.

Mantiply is another player the Mariners could look to upgrade their bullpen. Their two lefties in the pen are Tommy Milone and Ryan Borucki. Milone has pitched to a 3.45 ERA in 15 ²⁄₃ innings and Ryan Borucki a 1.93 ERA in 14 innings. Both lefties don’t have particularly strong peripherals, so adding Mantiply to their relief mix gives Seattle another match-up lefty who can pitch in setup duty if there are a string of left-handed bats. Mantiply is also capable of getting right-handed hitters out, although less effectively in recent outings, so Scott Servais doesn’t have to sweat if the opposing manager sends in a right-handed pinch hitter.

The clock is ticking for the D-backs to make moves ahead of the deadline and the Mariners are obvious buyers after trading for Castillo. Even though Seattle traded most of their top prospects in the trade, the cost to pick up David Peralta or Joe Mantiply shouldn’t be too prohibitive for them. We’ll see how potential moves shape up over the next 100 hours.