Jordan Montgomery to the Rangers
The Rangers pitching last year was abysmal, that is until they got Jordan Montgomery, who took over and led that staff to a World Series. He is the most consistent pitcher in a staff full of inconsistencies in Nathan Eovalid, Max Scherzer and Jacob DeGrom. In his time with the Rangers, he went 4-2 with a 2.79 ERA and an impressive 7.7 K/9 and elite 1.7 BB/9. Montgomery was really good for the Rangers down the stretch and provided a lot of stability for a rotation and bullpen that badly needed it during its postseason run.
The Rangers offense is elite, they don't need a lot of help on that side of the ball. If there were able to add a starting pitcher that has combined for over 10 fWAR over the last 3 years that would be a huge addition for them. Prior to his addition, the Rangers didn't really have a pitcher that could go toe-to-toe with any of the Mariner's starters. While the Mariners staff as a whole, is better than the Rangers, Montgomery is a very good starter.
Ideally for the Mariners, Montgomery gets a really good offer from another team really pushing to compete this year, maybe even a big market team like the Dodgers, Giants, or Cubs. Perhaps the teams that lose out on Yamamoto will turn to Montgomery and get him out of the AL West, that would help the Mariners out a ton.