PHOENIX — Center fielder Chris Young and the Arizona Diamondbacks have agreed to terms on a five-year contract extension through 2013.

The agreement, which includes a team option for 2014, was confirmed by a person familiar with the details who spoke on condition of anonymity because an announcement had not been made. The deal is likely to be announced tomorrow.

Terms of the contract approach the $31 million, six-year deal that Colorado shortstop Troy Tulowitzki agreed to in January, the person familiar with the details said.

Young, entering his second big league season, declined to comment on the contract situation before the Diamondbacks played their home opener Monday night against the Los Angeles Dodgers.

Thee dynamic 24-year-old outfielder came to the Diamondbacks in December 2005 as part of the trade that sent right-hander Javier Vazquez to the Chicago White Sox. Arizona also acquired right-handers Orlando Hernandez and Luis Vizcaino in the deal.

After spending most of 2006 with Triple-A Tucson, Young had one of the best rookie seasons in the Diamondbacks' 10-year history.

Mostly batting leadoff last year, he established rookie franchise highs in homers (32), runs (85), steals (27), doubles (29), slugging percentage (.467) and extra-base hits (64).

Young was the first rookie in major league history with at least 30 homers and 25 stolen bases. Only one other rookie, Nomar Garciaparra in 1997, had 30 homers and at least 20 stolen bases.

Young's nine leadoff homers led the majors.

His batting average, though, was just .237, a figure that manager Bob Melvin expects to rise considerably this year.

Entering Monday night's game, Young was hitting .217 with three home runs, four RBIs and seven runs. Two of his homers, including the 10th of his career leading off a game, came Saturday night in Arizona's 7-2 victory at Colorado.

Young was a 16th-round pick of the White Sox in the 2001 amateur draft out of Bellaire High School in Houston.