Upton Jr. has yet to suit up in a game for the Friars this season due to a left toe injury he suffered early in spring training.
He began a rehab assignment with the team’s Triple-A affiliate last Monday, and will need at least 40 at bats in the minors before he is activated from the disabled list, according to CBS Sports.
Upton currently has 21 at bats with the Triple-A El Paso Chihuahuas and is batting .190 with an RBI and seven strikeouts.
The Padres are on the hook for over $30 million of the five-year $72.25 million contract that he signed with the Braves in 2013. During his time with the Braves, Upton Jr. struggled mightily, batting .198 with a 324:101 strikeout-to-walk ratio over two seasons.
He found more success in the first eight years of his career with the Tampa Bay Rays, where he batted .255 with 232 stolen bases and sported a .336 on-base percentage.
With the absence of Wil Myers due to left wrist tendinitis, Upton Jr. may have a chance to get playing time in the majors right away once he is activated from the disabled list.