Ace Reese, the Mariners’ top pick from this year’s draft, stepped onto the field at T-Mobile Park on Monday. The young outfield prospect spent time at Pike Place Market, the Space Needle, and shook hands with Mariners officials. He also worked through a batting practice on the field. Seattle called his number four days earlier with the top slot from Walton High School in Marietta. His advisor, Scott Boras, connected with team personnel to lay out the club’s draft plans for Reese’s development.