"We finally came to a deal," Mier, who will receive a $1,358,000 signing bonus, said from his home in California. "I'm glad we came to a conclusion and my [agents] got it done. I'm trying to get out there and play."
Astros assistant general manger/director of scouting Bobby Heck wouldn't confirm a deal was in place, but the confirmation from Mier comes after multiple media reports that the Astros and Mier had reached a deal.
Mier, 18, is a 6-foot-2, 175-pound right-handed hitter with a power arm who hit .394 with 10 doubles, five home runs, 18 RBIs and 22 walks and had a .545 on-base percentage in his senior season at Bonita High School in Laverne, Calif.
Mier, who was picked No. 21 overall, said he will arrive in Houston on Thursday and be at Minute Maid Park on Friday after taking a physical.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.