The Diamondbacks want Gerardo Parra to be more selective in his at-bats. ''If he were more selective I think you'd see more damage out of him," manager Kirk Gibson said. "But it's a process. Trust me. He's a darn good player now." Parra has five home runs in 174 plate appearances, giving him an average of one home run every 34.8 at-bats. "He needs to have a better understanding of what pitch it is that he hits out," Gibson added. "If he's more selective, then you could see more consistent power numbers out of him."