Justin Upton is still a member of the Arizona Diamondbacks, but not for a lack of effort by the D-backs in trying to move him.

The Diamondbacks were in agreement on a trade that would have sent Upton to the Seattle Mariners, but the two-time All-Star rejected the proposed deal, according to major league sources.

The Mariners are one of four clubs on Upton's no-trade list, according to sources. At least two other teams, the Texas Rangers and Atlanta Braves, also are pursuing him.

The D-backs would have received a package of young talent from the Mariners. According to CBS Sports, that package would have included relievers Charlie Furbush and Stephen Pryor, minor league shortstop Nick Franklin and one of the Mariners' top minor league starting pitching prospects, right-hander Taijuan Walker, left-hander James Paxton or lefty Danny Hultzen.

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 be revived.

Upton, 25, is under contract for $38.5 million over the next three years. He has been the subject of repeated trade discussions almost since the moment that Kevin Towers became the D-backs' GM in the fall of 2010.

Both the Rangers and Braves have pursued Upton this offseason, sources say, and other teams also have checked in.

The Rangers have made three straight postseason appearances, twice reaching the World Series. The Braves recently signed Upton's older brother, B.J., to a five-year, $75.25 million free-agent contract.

The Mariners, on the other hand, have finished last in the AL West in each of the past three seasons and four of the past five. They play in a pitchers' park, Safeco Field, but are moving in the fences this season in an attempt to make the park more hitter-friendly.