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6/23/2014 6:21 P.M. ET

Mariners sign first-round Draft pick Alex Jackson

Jackson was rated by Baseball America as the top position player heading into the Draft

SEATTLE, Wash. -- The Seattle Mariners have signed Alex Jackson from Rancho Bernardo (CA) High School, the club's first selection (6th overall pick) in the 2014 June Amateur Draft, Director of Amateur Scouting Tom McNamara announced today.

Jackson, 18, hit .400 (40x100) with a 1.459 OPS and 45 runs scored, 7 doubles, 4 triples, 11 home runs, 31 RBI in 35 games during his senior season at Rancho Bernardo High School. Jackson helped lead Broncos to a 30-4 record and a No. 1 ranking heading in the playoffs this year, but were eliminated in the semifinals by La Costa Canyon Tuesday night. The Bronocs were rated as the 6th-best team in the nation by Baseball America in 2014. Other notable high draft picks out of Rancho Bernardo include Cole Hammels (17th overall in 2002) and Hank Blalock (3rd round in 1999).

The 6-foot-2, 215-pounder was primarily a catcher in high school and was rated by Baseball America as the top position player in the draft (4th overall prospect). Jackson was also named to the 2014 Perfect Game First Team All-American and California All-Region First Team after his senior season.

In four seasons with Rancho Bernardo, Jackson batted .375 (150x400) with 156 runs scored, 35 doubles, 6 triples, 47 home runs and 127 RBI in 135 games with the Broncos. His 47 prep career home runs tied him with former Indians prospect Johnny Drennen (2002-05) for the all-time San Diego section record. Jackson had 5 homers as a freshman, 17 as a sophomore, 14 as a junior and 11 during his senior season. Jackson's team played for California's San Diego section championship in all four of his high school seasons, including winning the championship during his freshman and junior seasons.

Jackson will report to the rookie-level Arizona League Mariners in Peoria, AZ tomorrow.

This story was not subject to the approval of Major League Baseball or its clubs.