He also has been a great teammate.
"He's an honest player, [something] we have not had on this team before," center fielder Ichiro Suzuki said. "He doesn't care what other people think about him. I think this team had too many players who were the opposite, and cared too much about what other people were thinking about them. He doesn't care. He shows that with his actions, and I think other players on the team are influenced by that."
Thanks in large part to Guillen's influence, on the field and in the clubhouse, the Mariners have gone from a last-place team in the American League West three years in a row to a playoff contender.
When the upcoming three-game series against the defending AL champion Tigers ends on Sunday afternoon at Comerica Park, three weeks will remain in the regular season. It's still a little too early to know if this will be a September to remember for the Mariners, but it already has been a summer to savor for Guillen.
"It has been a lot of fun this year," Guillen said. "The main thing that has made me happy is that I am healthy again. I had to prove to a lot of people that I am back. I even had to prove that to myself."
A solid work ethic and a training staff that he calls "the best I've ever been around" has made for what Guillen calls, "A special season."
"If not for [head trainer] Rick [Griffin] and his staff, I would not be playing this year. I was not healthy the first two months of the season. My elbow was still sore. But they kept working on it and now I am completely healthy."
The Mariners signed the 31-year-old to a one-year, $5.5 million contract last December. The deal included a mutual, one-year option for 2008, worth a base salary of $9 million, or a $500,000 buyout. As of Thursday, discussions on a contract extension were ongoing.
Guillen says he wants to return next season -- and beyond.
"It's like a family here, and it's hard to find that," he said. "There are not a lot of clubhouses like this."
And Guillen knows clubhouses.
The Mariners are his eighth organization in a 10-year Major League career, and he developed a checkered reputation along the way. The general opinion of him was that he had a bad attitude, a bad temper, and shot from the lip too often.
"He brought a lot of that on himself," manager John McLaren said. "But once you get to know him, he's a good person and a great teammate."
"He always has been a tremendous talent," said Mariners left-hander Jarrod Washburn, who was Guillen's teammate with the Angels during a cantankerous 2004 season.
"Even when he had our issues in Anaheim, I always said that 90 percent of the time he was a great guy and a great teammate. This year he added that other 10 percent."
Guillen and Angels manager Mike Scioscia had a bitter fallout late in the '04 season, leading to one of the team's most productive offensive players being suspended for the remainder of the season and the playoffs.
"He had a short fuse about things back then," Washburn said. "He's still vocal, and that's great. I love it. But you don't see him blow up as fast as he used to."
Washburn credits maturity for the change.
"Like anyone who plays a long time, including me, you grow up as you get older," said Washburn. "Jose and I have gotten along great this year. We haven't had any problems at all. It's been good. We talked early on in Spring Training. Both of us kind of had some questions and some doubts, but I think we've done a lot more talking as year has gone on. Now we talk to each other quite a bit. We have a good relationship."
The relationships developed inside the clubhouse have been instrumental in the Mariners' pursuit of a playoff spot. Everyone has been on the same page from day one of camp.
"We all get along and you never see anyone pointing fingers," Guillen said. "It's great when you have a clubhouse like this. I have been in a lot of clubhouses, and this is a great clubhouse."
Guillen wasn't sure what to expect when he arrived for Spring Training in Peoria, Ariz., in late February and the feeling was mutual. After all, it was difficult for anyone to get too excited about a player that hit .216, had his right elbow repaired via Tommy John surgery just eight months earlier, and had a bad reputation.
"No one really knew what to expect," closer J.J. Putz said, "but I don't think there is anyone in here that doesn't want him on this team."
Guillen said he had to show his new teammates what he was all about, "so they would respect me as a player and a person. I have a love for the game and a passion for playing it and I think guys respect that."
He has driven his point home quite well, thank you. His .287 batting average, 19 home runs and 84 RBIs rank him near the top in all of the team's offensive-production categories.
"Jose has a lot of grit about him and has really taken his game to the next level," McLaren said. "He has been good for the young players, and the veterans, by taking a leadership role onto himself.
"We know he likes to have fun, but he's really done a nice job on the bench, talking, pushing the guys, pulling for guys, whatever it takes. He has been absolutely great for our ballclub."
McLaren says Guillen is the kind of player that makes teams better.
"For me, those are the guys you want to be in foxhole with and I would certainly want him in my foxhole anytime," said McLaren.