New York Yankees general manager Brian Cashman said Wednesday that Masahiro Tanaka, the ace of his pitching staff, is still feeling discomfort in his pitching elbow despite not having picked up a baseball since receiving a platelet-rich plasma injection 10 days ago.

Speaking on ESPN New York 98.7 FM's "The Michael Kay Show," Cashman gave the following update on Tanaka: "He's improved, but he still feels it, although on a daily basis it decreases. So that's good but it's not good that he's still feeling it at this stage. So it's just day-by-day, week-by-week and we'll adjust accordingly. It's too early to call."

Tanaka was diagnosed with a partially-torn ulnar collateral ligament via MRI after complaining of elbow pain following an ineffective performance against the Indians in Cleveland on July 8.

He was subsequently examined by Yankees team doctor Christopher Ahmad, Los Angeles Dodgers team doctor Neal elAttrache and elbow specialist Dr. James Andrews, all of whom recommended the Yankees attempt to rehabilitate Tanaka's injury with a PRP injection followed by a throwing program, rather than the more standard, and radical, course of action -- Tommy John surgery.

Cashman defended the decision to forego surgery -- which entails a full year of recovery time -- on the basis that Tanaka might not be the same pitcher afterward.

"We get directed by what our medical experts say," Cashman said. "It was a unanimous decision and none of them recommended surgery. There's no guarantee that Tanaka if he has the surgery will be back to what he was."

Cashman cited the case of Manny Banuelos, a left-handed phenom in the Yankees farm system who underwent the procedure in October 2012 and has yet to return to his previous form.

"There's a high rate of success with the surgery," Cashman said, "But certain guys, they're not the same when they come back. Banuelos is coming back from Tommy John and now isn't really back to what he was before the surgery."

Earlier in the day, manager Joe Girardi had brushed aside a question about Tanaka, saying it would take a minimum of three weeks to know if the treatment was having a positive effect.