2B - Carlos Guillen - (1/8/2004) Carlos Guillen to the Detroit Tigers for Ramon Santiago and Juan Gonzalez.
Guillen came up with the Mariners after joining the club after a deal that sent Freddy Garcia, John Halama, and Guillen to Seattle from Houston for Hall of Famer Randy Johnson. Guillen played in just 15 games during the 1998 and 1999 seasons but began seeing more playing time in 2000 and 2001.
The 2001 season marked the best season of his career in Seattle, before being shipped off to Detroit following the 2003 season. What did he do in his first year with the Tigers? In typical Mariners' fashion, he did make the All-Star team and even finished off the year batting .318 in 136 games. This was not his only All-Star caliber season, as he also received the nod in 2007 and 2008.
Overall, Guillen posted a 9.6 WAR in 6 seasons in Seattle, compared to his 18.6 WAR in 8 years with the Tigers. Although the Mariners had SS Yuniesky Betancourt and 2B Jose Lopez up the middle during the mid-to-late 2000's, Guillen certainly would have been an upgrade over either of them.
Safe to say Juan Gonzalez (Not THE Juan Gonzalez) and Ramon Santiago did not end up as real valuable pieces for this team. It was tough not to go with Ketel Marte in this slot, but with what the Mariners got in return for Marte, I had to lean towards Guillen here. Even though he didn't play a ton there, it would've been easy to slot him into either of the middle infield spots. Due to the next person we are going to talk about, we end up saying welcome to our 2nd Base slot, Carlos.