After a hand specialist drained fluid from it on Tuesday, Upton hasn't swung the bat with his injured hand since.
"I haven't taken a hack with this hand, it's purely rest and treatment," he said. "It's coming along, it's better than it was a week ago; that's the positive thing."
That's not to say Upton hasn't swung at all. He has taken batting practice with his non-injured hand to try to keep active against live pitching.
"I've gone down to the cage and used the good arm to try to stay fresh and get my work in," he said. "I'm doing everything I can."
On Thursday, D-backs manager Kirk Gibson mentioned that Upton saw Mets third baseman David Wright on TV squeezing silly putty to keep his injured finger loose. Trainers use it to help keep stiffness out when the joints aren't being used.
"It's standard in the training room. The putty is one of those strength things," Upton said. "So, we're at that point now to try to get some flexibility in it."