Mobile BayBears' outfielder Justin Upton, the 2005 No. 1 overall pick in the Major League draft, is headed to the Arizona Diamondbacks, the Press-Register learned late Wednesday after the BayBears' doubleheader at Hank Aaron Stadium.

He made an immediate impact when he arrived in Mobile, hitting a home run in his first at-bat as a BayBear on May 13 and hitting three home runs in his first two BayBears games. He opened the season in Single-A Visalia where he hit .341 and had five homers in the month of April.

Upton played 70 games for Mobile, producing a .310 batting average. He also had 13 home runs and 53 runs batted in.

In the BayBears' first year as the Diamondbacks Double-A affiliate, two Mobile players already have been called up to the majors. The first was infielder Mark Reynolds, who was called up in late May.

Upton is expected to fly out early this morning to join the Diamondbacks.