So there stood a wiry Clayton, looking younger than his 37 years on his first day at Spring Training with the Blue Jays on Tuesday. He's entering his 17th season in the Majors and credits his wife, Samantha, for helping prolong his days in a baseball uniform.
Clayton's wife, who competed for Great Britain as a 200-meter sprinter in the 2000 Sydney Olympics, helped him focus on building up endurance and strength in his legs. Clayton said it's that type of training program that has enabled him to play in 130 or more games in 11 of his last 14 seasons.
"You can ask any player. The first thing to go are your legs," Clayton said. "In that era, when everyone was getting top-heavy and trying to hit the ball out of the ballpark, you saw a lot of leg injuries, because that part of the game was being neglected."
Still, Clayton admits that it was tempting to divert from his style of play. He has been heralded for his glovework, but his offensive production wasn't at the same level as the elite shortstops who have changed the way people view the position.
Clayton saw other shortstops hitting upwards of 30 home runs each year, whereas he never managed more than 14 in a season. Once he realized he didn't fit in the same mold as those other players, Clayton became more content with the kind of athlete he was going to continue to be.
"You kind of question your progress as a player," admitted Clayton, when asked how it felt to see other shortstops put up such lofty numbers. "It's just a self evaluation. I'm not going to accuse anybody, but whatever was being done, the longevity of seeing my kids grow up and my livelihood were more important."
Clayton and his wife of five years have four children -- two boys and two girls -- under four years of age. That includes the 15-month-old triplets that now occupy most of he and his wife's time at their home in Arizona.
The Blue Jays didn't sign Clayton in November because they needed another offensive weapon -- Toronto's lineup was potent enough. The Jays wanted to strengthen their defense up the middle and the club felt Clayton's experience could help.
Clayton is projected to be Toronto's starter at short, but veteran infielder John McDonald will see playing time at the position, too. Toronto believes both Clayton and McDonald can aid the development of young second baseman Aaron Hill.
"He's going to bring invaluable experience," Toronto manager John Gibbons said. "Johnny Mac gave us some of that last year, and Royce is going to do it this year. That will only make it better for Hill out there."
Clayton remembers when former Giants second baseman Robby Thompson helped give him tips when he was a young shortstop in San Francisco. Clayton also spent time in St. Louis watching and learning from Hall of Famer Ozzie Smith. Now, Clayton is looking forward to his role as one of the teachers on Toronto's roster.
"It's come full circle. I've had some great teachers in my time," Clayton said with a smile. "I think it's even more gratifying to have the respect of your peers and having young kids looking to you for assistance. I prepare for that role and teaching actually helps me, too."
Clayton doesn't want to be perceived as simply a glove-for-hire, though. Last season, he posted a .258 batting average with two homers and 40 RBIs in 137 games with the Nationals and Reds, but Clayton believes he can do the small things that can't always be measured in numbers.
"I work on every part of the game," Clayton said. "I don't want to just be known as a guy who just goes out there and makes the plays. I think I've contributed offensively -- driving in runs, moving runners, doing little subtle things that are kind of overlooked."
Clayton added that he feels prepared to play in 140-150 games this season, if that's what the Blue Jays need. The way he's forced himself to train over the years, resisting the temptation to stray from his style of play, has instilled that kind of confidence in himself.
Having his wife at his side has certainly helped.
"My wife has had a lot to do with it," Clayton said. "We have four kids, so I can probably get her [in a race] now. But at her peak, I wouldn't challenge her in her event by any means."