The Arizona Diamondbacks have called up infielder and top prospect Jordan Lawlar from Triple-A Reno. The D-backs also activated right-hander Kendall Graveman from the 15-day injured list, giving the team much-needed bullpen help. Arizona designated infielder Garrett Hampson and left-hander Jose Castillo for assignment as corresponding moves. The speedy, right-handed Lawlar — who just won Pacific Coast League Player of the Month for April — will join the club in San Francisco, as the D-backs are set to begin a three-game series with the Giants on Monday. Lawlar has dominated Triple-A pitching this season with a slash line of .336/.413/.579, six home runs, 15 doubles and 13 stolen bases in 37 games. -- Alex Weiner, D-backs reporter