San Diego manager Bud Black said the test, conducted in San Diego, showed no structural damage.
"It showed some inflammation around the joint," Black said. "Now it's just a matter of quieting down the wrist. Right now, it's angry."
Maybin, who missed his fourth consecutive game on Tuesday, is currently taking anti-inflammatory medication, Black said.
Black isn't sure when Maybin will play again, though he did say, "We'll see about this weekend."
The Padres are off on Thursday, which will give Maybin's wrist another day to heal. The injury first occurred "a month or two ago" Maybin said, though he is not entirely certain when.
Maybin does know that he aggravated the injury making a leaping catch at the wall in Arizona on Friday, as he used the wrist to brace himself against the wall. He then used that hand to help brace his return to the ground after making the catch.
Will Venable got his fourth consecutive start in center field on Tuesday to spell Maybin. The Padres also recalled outfielder Blake Tekotte from Double-A San Antonio to give them more outfield depth.