Out since April 30 with a partially torn left hamstring, Longoria has struggled at the plate for the Bulls, going just 4-for-27 with six walks and 2 RBIs. Each of his appearances has been as the designated hitter, and he isn't likely to see action in the field when he does eventually return to the Majors.
"We're just relying on the people there watching him, and him," Rays manager Joe Maddon said of Longoria's progress. "We're still gonna be patient with that until we get all the right answers."
Longoria missed Tuesday's game because of "soreness" but has been in the lineup for Durham's last three games, going 1-for-10.
He will be re-evaluated Monday by the Rays and could possibly be back for the team's upcoming series against the Blue Jays, which starts Tuesday, but Maddon said the chances of that happening are "50-50."
"How he does [Sunday night] would really matter, he's gone several days in a row right now," Maddon said. "I think the bigger issue from what I'm hearing is more that how he feels at the plate than his body... I just don't know that he feels good in a baseball way hitting yet."
In 23 games prior to the injury, Longoria was batting .329 with four homers and 19 RBIs.
After throwing a three-inning simulated game Friday, Jeff Niemann is set to begin a rehab assignment with Class A Port Charlotte on Wednesday. The assignment is expected to be at least four starts, to help stretch him out so he can throw 100 pitches.
Niemann was struck in the leg by a line drive May 14, resulting in a fracture. He was 2-3 with a 3.38 ERA and 30 strikeouts prior to the injury.