Add the Oakland Athletics to the list of possible suitors for Justin Upton, if the Arizona Diamondbacks decide to move him.

According to Ken Rosenthal of FOXSports.com, the Diamondbacks' right fielder has removed the Athletics from his trade veto list, making a deal between the two clubs feasible.

The Athletics were on Upton's no-trade list. They no longer are, according to sources with knowledge of his contract.

Upton is permitted to block trades to four teams per season, according to the six-year, $51.25 million extension he signed with the D-backs in March 2010.

According to sources, Upton has altered his no-trade list this season and three of the four teams have now changed.

During the 2010-11 offseason, the four teams Upton could block trades to were the Oakland Athletics, Detroit Tigers, Kansas City Royals and Cleveland Indians.

The New York Yankees have since been added to Upton's list, although the other teams remain unknown.

The D-backs haven't decided if they will deal Upton but after sputtering out of the gate in the second half and the Athletics emerging as a surprise contender, you'd have to wonder if these two clubs could discuss a trade and see if there's a potential fit.

While a deal between the two still seems remote, the D-backs are now able to wheel and deal with Oakland.