Report: Justin Upton rejected trade to Mariners

The Arizona Diamondbacks agreed in principle on a trade that would have sent star young outfielder Justin Upton to the Seattle Mariners. But Upton rejected the trade, according to a report from Ken Rosenthal and Jon Paul Morosi at Fox Sports.

Upton's no-trade clause contains four teams, and the Mariners are one of the four on the list. Rosenthal and Morosi report that Arizona would have received a package of young players back from the Mariners. The Arizona Republic's Nick Piecoro, who confirmed the report, called the Mariners' package "substantial."

Rosenthal later reported that the Mariners offered one of top prospects Danny Hultzen, James Paxton or Taijuan Walker — plus Nick Franklin, Charlie Furbush and Stephen Pryor.

Upton has been the subject of trade rumors for more than two years now, and his name began popping up once again last week with the Mariners, Rangers and Braves. The Diamondbacks have stepped up efforts to move Upton after signing Cody Ross late last month, giving them a surplus of outfielders.

Rosenthal and Morosi surmise that both sides could be making a play to gain leverage in the latest discussions:

Upton's rejection of the Mariners could be an attempt by him to leverage the Diamondbacks into sending him to a more preferred destination. The D-Backs, meanwhile, could be telling Upton that Seattle is his only option if he wants to leave Arizona, and for that reason it’s always possible that a deal could revive.