Blocking balls, though, is something that he could still use some work on and something on which he continues to put in extra time.
"He's not as much of a blocker," D-backs manager Kirk Gibson said. "He likes to try and catch it, and when the ball stays down like that, [it goes through a catcher's legs]."
Gibson has needled Nieves about his blocking as a way of prodding the catcher.
"We've talked about it in a good way," Gibson said. "I said, 'Geez, I don't want to have to bring Tuffy in late in the game for you.' You say it kiddingly -- you're kidding, but you're half serious. He knows it's just a lapse."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.