Diamondbacks sign Upton on big six-year deal

TUCSON, Arizona (Reuters) - The Arizona Diamondbacks signed their promising outfielder Justin Upton to a six-year contract worth $51.25 million, the team announced on its website on Wednesday.

In the second richest deal in franchise history behind the $52.4 million Arizona gave pitcher Randy Johnson prior to the 1999 season, Upton will receive a $1.25 million signing bonus paid in two installments on April 15 and July 15.

In less than three full seasons in Arizona, the 22-year-old Upton has established himself as an emerging standout. He hit .300 with 26 home runs and 86 RBIs while making the All-Star Game last season.

"It's definitely nice, I'll tell you that," Upton told reporters.

"It's one of those things where with that comes some responsibility. The pressure is off, but there is a lot to live up to and I think I'm ready for that. I want to be great and if you want to be great you set your goals higher."

(Reporting by Jahmal Corner in Los Angeles; Editing by John O'Brien)