When shortstop Ezequiel Tovar made his major-league debut late last season, he was 21 years and 53 days old, making him the youngest position player in Rockies history. Maturity was his calling card. Now, Tovar needs every ounce of that maturity as he struggles through a difficult April. He entered the weekend slashing .180/.242/.246 with four doubles, no home runs and just four walks in 66 plate appearances.