Saturday is the first time this year the D-backs will need a fifth starter due to a couple of days off early in the schedule.
Benson outpitched Billy Buckner and Kevin Mulvey for the spot. Part of it was his performance this spring after being signed midway though camp to a Minor League contract. The other was his one Triple-A start this year when he held Salt Lake to two unearned runs over five innings.
"We know he can handle the big leagues being poised and used to pitching up at this level for so long," D-backs manager A.J. Hinch said.
Benson was the first overall pick in the 1996 First-Year Player Draft. Initially selected by the Pirates, Benson has also pitched for the Mets, Orioles and Rangers in parts of eight seasons. He had rotator cuff surgery in 2007 and did not pitch in the big leagues that year or in 2008. Last season he was 1-1 with an 8.46 ERA in eight games (two starts) for the Rangers.
Because he's not on the 40-man roster, the D-backs will need to clear a spot for Benson. One option would be to move Brandon Webb from the 15-day to the 60-day disabled list, meaning he could not return until late May.
Given that Webb has still not gotten back up on the mound, Hinch was asked if there was any way he could return before June.
"I don't know," he said. "I think it's getting close. I keep waiting for something to click for him. That's why I'm hesitant to give away the six weeks that it would take to get us to June. I stand behind my thought that we need him to be right when he gets back. I'd rather wait a little bit extra time to get him right so that we have him for the long haul."