"It's more contract language and a few more ancillary things in the contract to be hammered out," Jim Aiken told MLB.com. "Our advisors are working with the Astros' executives on the contract -- and once the Draft ends, then we're going to get back on it."
Aiken is only the third left-handed high school pitcher to be taken with the first-overall pick, joining Brien Taylor (Yankees, 1991) and Houston's David Clyde (Rangers, 1973). Aiken is the fifth lefty selected first overall, and the first since David Price was taken by Tampa Bay in 2007.
"I'm really excited," Brady Aiken told MLB.com. "I know my advisors and the Astros are talking and they've pretty much got it locked down. I'm really excited and can't wait to get out there and start playing for the Astros."
MLBPipeline.com's Jim Callis reported on Saturday the Astros and Aiken had agreed to a $6.5-million signing bonus, which would tie the record for the largest given to a high school pitcher. The Pirates gave Jameson Taillon a $6.5-million signing bonus after taking him with the second pick in 2010.
"I can't comment on it," said Astros scouting director Mike Elias. "It's not necessarily true, either. When we took Brady Aiken, we had a good idea of his signability -- and I expect Brady will sign and it shouldn't take too long. We wouldn't take a kid with the first pick in the country if we weren't confident we could sign him -- and those kids usually end up signing anyway. I don't think it will be long, but we don't have any agreement in place."
The slot value for the No. 1 overall pick is $7,922,100.
Once a contract agreement is announced, Aiken will be flown to Houston to take a physical and meet the media.
"I wanted to get out here and [get] started playing as soon as I could," Brady Aiken said. "The Astros, having the organization that they do have and the young players, young talent they have, it's important to get out there and get used to the system and their philosophy, so I can get to the bigs and help them win some games."
Aiken posted a 7-0 record and a 1.06 ERA in 11 starts in his senior season. He was a 2014 Perfect Game first team All-American and an All-Region first team in California. He led Team USA to the gold medal at the 18-and-under World Cup in Taiwan last September by winning both of his starts -- including a championship-game performance against Japan in which he struck out 10 and allowed one run over seven innings.