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04/13/2013 10:01 PM ET

Rosario showing improvement behind the dish

SAN DIEGO -- Rockies catcher Wilin Rosario committed 13 errors and 21 passed balls last season as a rookie, but he also threw out 32 percent on stolen-base attempts -- five points above the league average.

In Friday's 7-5 victory over the Padres, Rosario threw out two runners trying to steal second, and has beaten four of the six runners who have tested him.

Rosario has made noticeable improvement with his receiving. But if teams remember the struggles and are running because they want to take advantage, it's fine with him.

"Maybe they know about what I've done, maybe not," Rosario said. "I hope they don't and they'll keep running."

Rosario, who hit his fourth homer of the season Saturday off Padres starter Edinson Volquez in the second inning and then threw out Everth Cabrera at third for the third out in the third inning, was proud because Friday was not a good night offensively -- he struck out twice in key situations, although he did drive in a run on a fielder's choice -- so the team needed his defense.

"That's one of the best experiences I can have," Rosario said. "I want to be a winner. Not every time are you going to hit. The only thing you can control is your glove -- catching everything, blocking balls, stopping runners."

Weiss confident Lopez will find his rhythm

SAN DIEGO -- Rockies manager Walt Weiss said Saturday that he still believes in right-handed setup man Wilton Lopez, despite a 12.46 ERA that included a potentially game-turning two runs in the seventh inning of Friday night's 7-5 victory over the Padres.

Lopez, 29, posted sub-3.00 ERAs the last three years with the Astros, including time last year as the team's closer. The Rockies acquired him during the winter for right-hander Alex White, who recently underwent Tommy John elbow surgery and will miss the rest of the season. To make the deal work for them, the Rockies need for Lopez to find his form.

Lopez began his Rockies career by giving up four hits and three runs in one inning against the Brewers to blow a lead on Opening Day -- a game the Rockies ended up losing in extra innings. Lopez has given up runs in three of his five appearances and has yielded a .520 opponents' batting average. But Weiss is not seeing warning signs of a pitcher that has either lost the chance to be effective or is hiding an injury.

"It looked like there was a lot of life to the ball," Weiss said. "He's been nicked a lot. There have been some infield hits, some strangely hit balls that have gotten through and then a guy will get a clean hit. I just don't think he's very far off from getting on a roll."

The Rockies acquired Lopez to pitch late in the game, often in the eighth inning as a setup man to Rafael Betancourt. Weiss is not looking to move Lopez out of the late-inning mix, although he can also turn to right-hander Matt Belisle and lefty Rex Brothers to protect leads.

"I've got to be honest with you, every time I bring him in, I think he's going to be lights-out," Weiss said. "We'll play that by ear. We'll put him in the best possible position to be successful. He's still going to get meaningful innings. I don't know when exactly that's going to be. Is it going to be the seventh or the eighth? They're still going to be meaningful outings."

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.