"It's hard because you only make this decision one time in your career and in your life."
Guillen played the past eight seasons for the Tigers, for whom he made the American League All-Star team in 2004, '07 and '08 and helped Detroit reach the World Series in 2006.
He began his career with Seattle from 1998-03 and the Mariners brought him back this season with the idea that he might provide a veteran bat while competing at third base and providing a backup at first as well.
Chone Figgins and Kyle Seager have received the bulk of the work at third this spring, with Vinnie Catricala also getting a good look there after being named the club's Minor League Player of the Year last season following a strong year in Class A and Double-A.
Guillen hit .285 with 124 home runs and 660 RBIs in 1,305 games in his 14 seasons in the Majors. He appeared in six postseasons, batting .344 in 19 games. His walk-off squeeze-bunt single to score Rickey Henderson in the bottom of the ninth inning of Game 3 at Safeco Field clinched the Mariners' sweep of the 2000 AL Division Series against the White Sox.
"That was an exciting moment, one of the best of my career," Guillen said. "Lou [Piniella] had a lot of confidence in me and he told me he wanted me to hit a ground ball to first base. The first pitch I thought, 'Well, maybe a deep fly ball would bring the winning run in.' So I swung at the first pitch and he said, 'Hey, son, what did I tell you?'
"I said, 'OK, OK.' And I just thought if he throws me a fastball inside, it's going to be hard to hit a ground ball to first base," he said. "So I had to find a way and I thought, 'Maybe I'll drag a bunt.' Then the ball went through and we won the ballgame. It was a great moment for me and the fans in Seattle and everybody because when you win, you're having fun."
It's those sorts of memories that brought Guillen to Peoria this spring for another shot with the Mariners, though he didn't come thinking of ending his career where it started.
"My first two boys were born in Seattle, so that's why I wanted to come here," he said. "I never thought to end my career here, but I feel like I have to. I learned a lot of good things from Jay Buhner and all the players when I was here -- Edgar Martinez, Junior, A-Rod. They were fun years for me and the fans in Seattle."
Guillen originally joined Seattle, along with pitchers Freddy Garcia and John Halama, in a trade with the Astros for Randy Johnson. That trio helped the Mariners win 116 games in 2001, though Guillen's best success came after he was traded to the Tigers in '04.
"I'm going to miss a lot of things," said the Venezuelan native. "A lot of people love you and are cheering for you when you're in the stadium. I always have fun and enjoy being around players and the clubhouse. It's going to be different, a big change."