The American sustained two small fractures to his right hand in a violent Indianapolis qualifying accident which also briefly knocked him out in August last year.
He then aggravated the injury at Aragon when he flew over the track perimeter in a second-lap crash.
With Ducati not attending next week's private test at Austin, Hayden took advantage of his break from testing to have a small operation, which he tweeted was to "clean up some old scar tissue."
Yamaha, Honda and its satellite LCR squad are the only three teams due to head out to Austin for next week's three-day test.
The next official MotoGP test takes place at Jerez on March 23-25.