The selection, which the club received as compensation for losing pitcher Jason Marquis to the Nationals via free agency, came after the club selected Clemson outfielder Kyle Parker with the 26th overall choice.
Tago made a major impression when he struck out 13, gave up seven hits and walked two in helping his unseeded Dana Hills team to a 5-3 victory over Placentia El Dorado in the California Southern Section Division 1 semifinals. Tago's team, however, lost to Santa Ana Mater Dei in the finals when two opposing pitchers combined for a perfect game.
"The other day in the CIF Playoffs in Southern California, he was up to 96 [mph], but he's usually 91-93, but a lot of upside there," Rockies vice president of scouting Bill Schmidt said. "He has a chance to be real good."
Tago is listed in the 6-foot-3 to 6-foot-4 range, with weight listings anywhere from 160 to 190. Whatever the numbers are, they're likely to change with maturity.
"He's very projectable, probably along the line of Esmil Rogers -- a Pedro Astacio-type arm, a loose, projectable arm," Schmidt said. "Our people, our pitching coordinators and [assistant general manager] Bill Geivett, have been out to see him. A lot of people think that he'll develop."
Both picks illustrated the Rockies' "best athlete available" selection philosophy.
Parker, a power hitter for three years at Clemson, made the freshman All-Atlantic Coast Conference team in football last fall as a quarterback. He is considered an NFL prospect.
Tago is committed to Cal State Fullerton for baseball. Earlier, he had committed to UCLA. Competition with another sport or with a traditional baseball power does not frighten the Rockies, who used their top choice last year on a high school pitcher -- lefty Tyler Matzek of Capistrano Valley (Calif.) High School, who signed a pro contract.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.