One day after Dioner Navarro homered in his first Cactus League at-bat for the Cubs, Welington Castillo smoked his first spring home run Monday against the Dodgers. "If he asks, I'm going to let him know, 'I hit one longer than yours,' " Castillo said. Suffice it to say there won't be any crowds on Waveland Avenue this summer waiting for shots to leave the yard off the bats of Cubs catchers. But the organization feels confident the tandem of Castillo and Navarro will provide more offense than last year's season-opening duo of Geovany Soto and Steve Clevenger, while also guiding a veteran pitching staff. Clevenger is slated for Triple-A Iowa, and Castillo has been handed the starting job after hitting .265 with five home runs and 22 RBIs in 52 games in 2012. He took over for Soto after the veteran was dealt to the Rangers at the trade deadline, and he could be part of the core if he has a solid season. "It feels good, but I'm not going to take anything for granted," Castillo said. "I'm going to work hard like I'm fighting for a job. I don't like feeling comfortable. That does help, coming to spring training and knowing you've got a job."