By Mark Bowman

The Braves have reached a preliminary agreement to acquire Justin Upton from the D-backs in exchange for four players, including Martin Prado.

According to a Major League source, the Braves will get Upton and Chris Johnson in exchange for Prado, shortstop prospect Nick Ahmed and right-handed pitchers Randall Delgado and Zeke Spruill. This deal is pending the completion of physicals.

With this trade, Braves general manager Frank Wren provide his club the game’s best outfield. He began this offseason by signing Justin Upton’s older brother, B.J. Upton to a five-year, $75.25 million contract. His projected outfield over the next three seasons will consist of Jason Heyward and the two Upton brothers.

To complete this trade, Wren had to part ways with Prado, who is one of the Braves’ most popular players among the fans and his teammates. But he was able to acquire Upton without giving up either of his top two pitching prospects, Julio Teheran or J.R. Graham.

The departure of the versatile Prado signals that the Braves will likely enter the season with Juan Francisco and Johnson sharing the third base duties.

Upton has hit .278 with 108 homers and a .832 OPS since making his Major League debut during the 2007 season. The 25-year-old outfielder was one of the game’s top outfielders as he hit .289 with 31 homers and a .898 OPS in 2011 with the D-backs. A thumb injury limited him this year as he hit .280 with 17 homers and a .785 OPS.