For a Rockies' offense struggling to find its identity and produce some power this season, the test began Thursday night in the season-opener against Arizona right-hander Zac Gallen.
Brenton Doyle uses medicine ball to help swing mlb.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from mlb.com Daily Mail and Mail on Sunday newspapers.
Rockies center fielder Brenton Doyle won a Gold Glove as a rookie but he struggled to hit. His offseason was dedicated to improving his apporach at the plate.