"I was proud of the way everybody worked very hard and challenged themselves," Melvin said before Wednesday's Tucson finale with the White Sox. "Across the board, we got better. We made them do some things that at times they were uncomfortable with, but you have to find out, to know how good you are going into the season, and you make some mistakes doing it. We've been pretty demanding on these guys. This is probably the hardest-working camp I've been a part of as a manager."
In addition to the ongoing challenge of finding a fifth starter and the competition to round out the reserve spots on the roster, one of the biggest challenges for the D-backs has been to stay healthy. They've met that challenge, with Randy Johnson on pace for a mid-April appearance in the rotation and projected starting right fielder Carlos Quentin progressing steadily after he suffered a shoulder injury during an at-bat against Oakland on March 16.
"The more games he played, the more confidence he was getting," Melvin said of the 24-year-old Quentin, who debuted with the D-backs in July. "He's a guy we expect to drive in a lot of runs."
Quentin was hitting .357 (10-for-28) with three homers and 10 RBIs in his 11 games before the injury. After playing soft toss Tuesday and working in the batting cage, Quentin took batting practice on the field before Wednesday's game.
"It went well," Quentin said of his first live BP in nearly two weeks. "I was swinging about 70, 80 percent. It felt good. The ball came off the bat well. There wasn't any pain."
Quentin will stay in Tucson on Thursday so he can play in a Minor League game. With four days left before Opening Day, the D-backs hope to get him an abundance of at-bats in Minor League games before the season starts, ideally making up the equivalent of six spring games.
"We don't want to push [Quentin]," Melvin said, putting the odds at 50-50 of Quentin breaking camp with the club. "We just want to see how he responds day-to-day. We've got contingency plans if he does and if he doesn't. He's a guy we have to be somewhat careful with."
One reason Melvin feels compelled to be careful with Quentin is his "max-effort" approach to the game. The injury came from Quentin's aggressive approach at the plate. He awkwardly swung at a high, inside pitch.
"I need to stay away from that," Quentin said. "We are trying to control the effort in the swing, but when you hit a certain way, that is tough to change. That's the one adjustment I can make -- don't swing at the high, inside pitches."
With his successful day of BP, Quentin is optimistic that his odds of appearing on the Opening Day roster should improve as steadily as his swing has.
"I'm still holding out [hope]," he said. "Today was good progress."
Making a grab: Dustin Nippert made a convincing case to be the D-backs' No. 5 starter on Wednesday. Nippert pitched five scoreless innings, facing a White Sox lineup with all its starters playing except Joe Crede. Nippert held the White Sox to four hits, while improving his record to 3-0 with a 2.30 ERA.
"I made a statement to myself that I can throw all my pitches for strikes and command my pitches," Nippert said. "The rest is up to them."
Melvin couldn't have been more complimentary of Nippert, emphasizing that he was "absolutely" still in the running for the job.
"Outstanding," Melvin said of Nippert's performance. "I don't know if you can pitch better than that. He used his two-seamer, he used his changeup in off counts, he had a good breaking ball. All the things that he needs to work on -- he was holding runners, he was quicker to the plate. He really brought it all together."
Hernandez hits 101: On the other side of the complex, Livan Hernandez threw 71 pitches -- and 30 more in the bullpen -- in six innings of two-run ball in a Minor League game, his final tune-up before starting the second game of the season in Colorado.
Hernandez said he hurt his arm "swinging too much" in batting practice early this week, but he felt no effect of it pitching Wednesday.
Staking their claim: The D-backs claimed a prized prospect from their division rivals in Colorado on Wednesday, picking up center fielder Jeff Salazar off waivers.
Salazar hit .283 in 19 games for the Rockies last September, knocking a homer and eight RBIs while stealing two bases.
Salazar faced a crowded field competing for a bench role in Colorado, with ex-Diamondback Steve Finley winning a spot as a non-roster invitee.
On deck: Johnson makes his first Cactus League start of the season Thursday against the Padres at 6:40 p.m. MST at Chase Field. Johnson is expected to pitch three innings, followed by fifth-starter candidate Micah Owings, who could go six.
"It should be interesting," Melvin said of the unique pairing. "Randy being the elder statesmen, and Micah being the up-and-comer that we think is going to have a sensational career. It's pretty exciting that both of these guys are going to be throwing in the same game, especially in front of our home crowd."
But don't expect any kind of symbolic passing of the torch from Johnson to Owings.
"If he passes a torch, he's probably got a few more sitting in his locker that he's going to keep lit," Melvin said.
Doug Davis will make a split-squad start earlier Thursday in Mesa, facing the Cubs at 12:05 p.m. MST.
Owen Perkins is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.