The Houston Astros are "highly unlikely" to be able to sign No. 1 overall pick Brady Aiken after the July 18 deadline, according to a source.

The source was surprised at a recent report that Houston could still sign the high school left-hander.

Bud Selig was asked by 10News, a San Diego television station, to address Aiken's situation on Wednesday and Selig said "we're working on that right now."

"There are a lot of things in movement there so it would be inappropriate for me to comment," Selig said, "but I would say we are working towards a hopeful solution."

According to the source, the commissioner could only have been referring to Jacob Nix, Houston's fifth-round draft pick, who also went unsigned and has filed a grievance against the Astros.

The Astros could be forced to sign Nix by an arbitrator.