There was reason to believe the mystery team might have been the Royals. But if that was the case, their interest in Upton was erased on Monday night when they reached an agreement with free agent outfielder Alex Rios.
The fluidity of the Hot Stove season can certainly alter a team's mindset on a daily and even hourly basis. Though Seattle general manager Jack Zduriencik has long coveted the possibility of acquiring Upton, last week he seemed more interested in adding Melky Cabrera to his outfield mix.
But now that Cabrera has signed with the White Sox, the Mariners are once again looking to add a bat to a lineup that was already bolstered by the signing of Nelson Cruz.
When the Padres landed Matt Kemp in a trade last week (deal is pending a physical), there was initially an assumption they would not continue to show interest in Upton. But San Diego's aggressive new general manager, A.J. Preller, seems to view Kemp's addition as simply further reason to talk to the Braves about the man who has hit the second-most home runs in the National League over the past two seasons.
The Padres have remained in contact with the Braves over the past few days, and at the same time, made it known that they would be willing to assume Upton's cost -- he is owed $14.5 million in 2015 -- with the understanding that he might remain in San Diego for just one year.
While the Braves are attempting to gain talent that has the potential to make an impact when SunTrust Park opens in 2017, the Padres are trying to immediately bolster an offense that proved to be the only one that scored fewer runs than Atlanta's this past season.
Upton was the most productive member of Atlanta's anemic offense in 2014. Thus, if the right deal does not materialize, the Braves might be persuaded by the temptation to keep Upton around for one more year with the hope that he becomes the latest of those elite players who seem to thrive during the final year of a contract.
But as the Braves look toward the future and continue to attempt to upgrade their farm system, they recognize that the value that would come via trade would likely trump the value of the compensatory Draft pick they would gain if Upton exited as a free agent following the 2015 season.
The Braves are still looking to add one Major League-ready starting pitcher and upgrade the organization's overall pitching depth. As they evaluate their trade options, they are also looking at outfielders that might make an impact within the next two years and third basemen.
Here is a quick look at some of the players that could interest the Braves as they evaluate deals that could involve Upton:
Padres: The Braves would certainly have interest in Andrew Cashner or Tyson Ross. But there has been no indication that San Diego would part with either of these two talented and seasoned pitchers. To get Upton, the Padres would likely have to deal at least one of these pitchers -- Matthew Wisler, Max Fried or Joe Ross (Tyson's younger brother).
While the Braves seem prepared to allow Christian Bethancourt to serve as their catcher of the future, it would be hard for them to back away if the Padres were willing to part with Austin Hedges -- regarded by one scout as the best high school defensive catcher he has ever seen. The presence of Hedges might push Bethancourt to increase his effort level, which has been questioned over the years.
Royals: While the Royals would likely be hesitant to include Kyle Zimmer, they might need to include left-hander Sean Manaea to get Upton. The Braves might also be interested in Miguel Almonte and Scott Blewett, a couple of other power arms in Kansas City's farm system. Atlanta asked for Yordano Ventura when the Royals expressed interest in Evan Gattis last month. Kansas City is certainly not going to part with Ventura for what might be one year of Upton.
Mariners: The Mariners will not part with Taijuan Walker or James Paxton for Upton. But the Braves might be interested in a package that includes Edwin Diaz or Victor Sanchez -- a pair of prospects who are at least a couple of years away from being Major League ready. Atlanta could also be interested in D.J. Peterson, whose bid to play third base in Seattle has been blocked by the emergence of Kyle Seager.
Giants: Kyle Crick, Tyler Beede and Adalberto Mejia headline a list of pitching prospects San Francisco could include in a deal for Upton. The Giants do not match up well with the Braves in terms of position-player prospects.