We have our first significant deal a week beforeMajor League Baseball's July 31trade deadline, with theArizona Diamondbackssending first basemanJosh Naylorto theSeattle Mariners, the teams announced Thursday night. The Diamondbacks are receiving rookie leftyBrandyn Garciaand pitching prospect Ashton Izzi in the deal. Naylor is slashing .292/.360/.447 this season, with 11 home runs, 59 RBIs and 11 stolen bases. The Diamondbacks had acquired Naylor in an offseason trade with the Guardians, with the slugger coming off a 31-homer, 108-RBI campaign in Cleveland. Naylor, 28, is a free agent at the end of the season, making him a rental for Seattle. Here's a breakdown of the deal: The Mariners were in desperate need of a corner bat and Naylor should immediately become the starting first baseman, pushing Luke Raley back to the outfield. Seattle's first basemen have combined to hit just .233 this season and Naylor slots nicely into the lineup, giving some legitimate protection to Julio Rodriguez,Cal Raleighand Randy Arozarena. If things go well over the next few months, perhaps Seattle considers signing Naylor to a multi-year deal come free agency. The first of many trade dominos to fall in Phoenix? Naylor is the first out the door in Arizona, but could soon be followed by a handful of teammates including third basemanEugenio Suárez The Diamondbacks landed two of the top 20 players in Seattle's farm system in Garcia (No. 13) and Izzi (No. 16). Garcia is a big-league ready arm who has pitched in relief this year, and the Diamondbacks will have to decide whether they see him as a starter or reliever in the long term. Seattle Mariners receive 1B Josh Naylor Arizona Diamondbacks receive LHP Brayden Garcia RHP Ashton Izzi Josh Naylor is making $10.9 million in 2025 and is a free agent at the end of the season. This article originally appeared on USA TODAY:Josh Naylor trade grades: Mariners, Diamondbacks MLB deadline deal