TUCSON, Ariz. -- Justin Upton has lived with high expectations virtually since the day he picked up a baseball bat.
Now at 22, with two full major league seasons already behind him, he says he welcomes the challenge of living up to the $51.25 million, six-year contract he signed on Wednesday with the Arizona Diamondbacks, the second-largest deal in franchise history.
With his parents Manny and Yvonne looking on proudly at a news conference, the outfielder said he understands the responsibility that comes with this big a contract at such a young age.
"I do kind of put that pressure on myself," he said. "I want to be great, that's the thing. If you want to be great, then you set your goals higher."
Upton earned his first All-Star berth last season, when he hit .300 with 26 homers and 86 RBIs.
His statistics are compared favorably with those of some of the game's greats at the same age. His OPS (on-base percentage plus slugging percentage) of .836 compares with the early numbers of Al Kaline, Mickey Mantle, Ted Williams, Ken Griffey Jr. and Alex Rodriguez.
"There's a lot to live up to," he said, "and I think I'm ready for that."
He gets a $1.25 million signing bonus, half on April 15 and the rest on July 15. He receives salaries of $500,000 this year, $4.25 million in 2011, $6.75 million in 2012, $9.75 million in 2013, $14.25 million in 2014 and $14.5 million in 2015.
"We view him as a core player, one of our key pieces," general manager Josh Byrnes said, "and as we view the next six years the kind of guy we want to build around."
The only bigger contract in Diamondbacks' history was the $52.4 million, four-year deal Randy Johnson signed in 1999.
"This is something you dream about. For it to come true, it really hasn't sunk in yet," Upton said. "My parents have definitely been a special part of my life to get me to this point. It's definitely a special day. I'm glad they could be here. I know they're as happy as I am."
Upton has had the pressure of high expectations for years, following the path of his older brother B.J., who was the No. 2 draft pick overall in 2002. Justin was one better, chosen No. 1 by Arizona in the 2005 draft.
He played less than two years in the minors before being called up by the Diamondbacks in 2007 one month shy of his 20th birthday.
Manager A.J. Hinch was the newly hired director of player personnel when Upton first was signed in January 2006.
"We know him very well. We have a great relationship. To be able to have him as a centerpiece of our organization is a great advantage," Hinch said. "He's already had productive seasons and he's still got a lot of room to grow, which is exciting to see and also scary for the National League."
While he has a quick, even picturesque, swing, his form in the outfield is a work in progress. Upton had played only eight games in right field in the minors before being installed there at the major league level in 2007.
Byrnes compared his outfield issues with "a young Vlad Guerrero," with the speed and talent to get to balls but not necessarily the finesse that comes from learning the position well.
Byrnes said that teams in markets like Arizona's have to make a move to keep their young talent as long as possible.
"We generally need to go early to deal with free agency, and we've done that in a number of cases," Byrnes said. "There might be more risk because you're going early and you're going longer, but I think the reward justifies those types of moves."
The general manager noted that Brandon Webb would not be under contract and Dan Haren would be entering his final year had the team not signed them early. Webb is in the final year of his contract.
However, sometimes contracts can backfire. Outfielder Chris Young's performance at the plate was dismal in the wake of the $28 million, five-year contract he signed in 2008, although he did improve after a stint with Triple-A Reno last season.
Upton said he considered going year by year in arbitration and eventual free agency before choosing security.
"They made a comfortable deal with the years. That's something that definitely factored in," he said. "I was comfortable with their proposal and the direction that they're going."
Upton's father said he didn't sleep too well the past few nights knowing the agreement was close. Plainly proud of both sons, he said he has to work on Justin not being so hard on himself during times of adversity.
"Sometimes I have to be the sounding board to make sure he's not beating himself up," Manny Upton said.
Justin Upton said he hasn't been sleeping too well lately, either.
"But now that it's over with everyone's happy," he said. "That's all that matters."