(SportsNetwork.com) - Pitching prospect Brady Aiken, the top overall selection in the 2014 draft, underwent Tommy John surgery on Wednesday.

Aiken was selected No. 1 overall by the Houston Astros, but the two sides could not agree on a contract before the mandated deadline, thus giving Aiken another chance to enter the draft.

Houston, which had concerns of Aiken's elbow during the negotiation process, reduced its original offer of $6.5 million down to $3.1 million before making one last effort with a $5 million deal that Aiken declined.

"Yesterday, I had Tommy John surgery to fix my left arm," Aiken wrote on The Players' Tribune website on Thursday. "I'm obviously extremely disappointed. I wanted to let my pitching speak for itself, but now there are going to be new distractions. For that reason, I wanted to be the one to tell people what's happened and make this a fresh start."

Aiken was pitching at the IMG Academy last week when the injury first occurred. He attended the academy rather than a four-year college so he can remain eligible for the 2015 draft, and he is considered to once again be a strong choice early in the first round.