There is a chance — a chance, mind you — that the Rockies will put their best starting rotation in franchise history on the mound this season. That tantalizing possibility is predicated on many things, but certainly, two things must happen. One, the Rockies’ core of young pitchers must stay healthy. Two, those pitchers must continue the maturation that began last season. The quest begins in earnest Wednesday at Salt River Fields in Scottsdale, Ariz., when pitchers and catchers gather for the first official workout of spring training. It promises to be an intriguing camp, with seven pitchers competing for five slots in the rotation. The seven: right-handers Jon Gray (age 26), Chad Bettis (28), German Marquez (22), Antonio Senzatela (23) and Jeff Hoffman (25); and left-handers Tyler Anderson (28) and Kyle Freeland (24). As a unit last season, those seven (plus Tyler Chatwood, who signed with the Cubs as a free agent in December), went 63-56 while compiling a 4.59 ERA, the fifth-lowest ERA in franchise history. “Last season spoke really highly of those guys,” said Bettis, who battled back from testicular cancer to make nine starts. “For them to be able to step up in that position, on the big stage, was huge. And none of them took it for granted, which was awesome. They have all been down here in (Arizona) working to get better. It’s a tight group. We’re all pushing each other to be better.” With Bettis out of action for much of last season while he battled cancer, and with Gray going on the disabled list April 14 because of a broken bone in his left foot, it looked as though the Rockies’ 2017 season would be a bust. Instead, the Rockies won 87 games and made it to the playoffs for the first time in eight years. “The success our young pitchers had gave them a little more fuel for this year,” Bettis said. “I mean, the critics came in and said, ‘Oh, the Rockies are falling apart with their pitching staff.’ So for those guys to step up was huge. At the same time, I think those guys understand what it will take to get better this season.” Improved pitch command, especially in key situations, as well as cutting down on walks, will be the primary focus this spring. Last year, the Rockies’ starters posted an 18.9 percent strikeout rate and an 8.4 percent walk rate, both among the worst of teams that made it to the playoffs.