The Arizona Diamondbacks are seriously discussing a trade of Justin Upton to the Atlanta Braves on Wednesday evening, according to sources.

A deal to the Braves would unite Upton with his older brother , B.J. Upton, who signed as a free agent with Atlanta this winter.

The Diamondbacks want to decide whether to trade Justin Upton after more than a year of dangling the young star outfielder in the trade market, or Jason Kubel sometime in the next 48 hours. A deal could happen as soon as Wednesday. Arizona has been discussing a possible Kubel deal with Baltimore, and sources involved in the Upton talks said Atlanta has made a strong offer that is likely built around pitching.

In any Upton deal, the Braves probably would surrender a package of prospects that won't include young shortstop Andrelton Simmons, a player Arizona asked for earlier in this offseason, sources said.

Upton was once viewed by the Diamondbacks as a player they would build around for years to come, and at age 21, he hit 26 homers, scored 84 runs and drove in 86 runs. In March 2010, Arizona signed Upton to a six-year, $51.5 million deal. Arizona made the playoffs in 2011, and Upton finished fourth in the NL MVP voting.