Rosario was decent against basestealers -- he threw out 30 of 94 (32 percent) -- last season. Controlling the running game was one area that Rosario, who struggled with receiving, showed well defensively.
Rosario has shown improvement at blocking balls and receiving this spring. If he proves to be a threat against the running game, he could take one worry off the minds of Rockies pitchers.
"I like to throw," said Rosario, who isn't bashful about throwing to first with either a left-hander (whose body screens the runner's vision of the catcher) or a righty batting. "I like to use my arm. I have quick feet. I'm trying to get advanced at that. I feel good when I do that.
"The sooner we can make the runners stay closer, the easier it is for the pitcher to pitch the game."
Veteran non-roster catcher Yorvit Torrealba accomplished a pickoff of this own Monday against the White Sox at Glendale, Ariz., when he erased Jordan Danks at third base in the third inning.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.