SCOTTSDALE, Ariz. — One thing’s for sure: Jon Gray doesn’t grade on the curve — especially when it comes to his own performance.

Wednesday, after tossing four scoreless innings against the Angels, striking out five and walking none, the Rockies’ right-hander offered up a critical assessment: “My B-minus, C-plus stuff.”

Hmm. Considering that Gray whiffed batters using a 95 mph fastball, a 90 mph slider and a 75 mph curveball, the grade seems a tad low. But Gray explained that he came out firing across his body with his fastball and slider and wasn’t able to fix it until the second inning.

“The more I was aware of it, the more I was able to fix it,” Gray said, noting that that was something he struggled to do last year when he finished 12-9 with a 5.12 ERA, didn’t make the postseason roster and needed a refresher course at Triple-A Albuquerque.

Gray has been mostly sharp in all three of his Cactus League outings, combing them for a a nine-inning line that reads: one run allowed on two hits, one walk and 10 strikeouts.

“He’s doing fine,” manager Bud Black said. “We’re trying to get him in a good spot with his delivery, which he’s doing. And he’s taking that out on the mound and reproducing what he’s been doing in his side work.”

Bullpen bound

Jesus Tinoco, the hard-throwing, 6-foot-4, 260-pound right-hander, is headed to the bullpen.

“I think there’s a little bit of upside on his stuff and the resiliency of the arm to get into that bullpen and maybe get to the big leagues a little sooner,” Black said.

The 23-year-old Tinoco, part of the 2015 late-July trade that sent Rockies shortstop Troy Tulowitzki to Toronto, has started 120 of 131 games during his minor-league career, including all 26 games for Double-A Hartford last season. But the Rockies now envision him as back-of the-game flamethrower.

“He is transitioning to a relief role, so that will be new for him. We think that’s where his future lies,” Black said.

Tinoco, in camp for the second time, is still searching for consistency. He posted a 4.79 ERA in 26 starts at Double-A Hartford last season, though he did strike out a career-high 132 batters.

Notable

Righty reliever DJ Johnson, a September call-up who earned a spot on the postseason roster last year, pitched another scoreless inning, his fourth of the spring. He has given up just one hit … Second-base candidate Garrett Hampson started in center field and led off. Hampson’s versatility is a key to him making the roster.