DENVER -- The Rockies presented left-handed pitching prospect Ryan Rolison with a gift for turning 23 on Saturday night: a start in the team¡¯s Summer Camp intrasquad game. It was up to Rolison to face down a solid lineup to make his birthday happy.

Rolison -- Colorado's first-round pick in the 2018 MLB Draft and its No. 2 prospect per MLB Pipeline -- walked Trevor Story with one out in the first inning. Then, Rolison got Nolan Arenado (who later homered twice) to ground into a double play.

Rolison is not in the Rockies' big league plans for 2020, but he's in camp because the Minor League season has been canceled and Colorado's staff wants to help him with some balance adjustments. He went two innings with no hits allowed and a strikeout.

¡°I was kind of frustrated that I let three pitches get away from me against Story and gave him a free bag,¡± Rolison said. ¡°I fell behind to Nolan, 1-0 -- missed with the fastball.

¡°My main focus has been developing my changeup, and I knew that situation was the perfect time to throw it. [Catcher] Tony [Wolters] threw down a changeup, and I was able to trust it. It was a good pitch, down in the zone, and got the result that I wanted.¡±

It was an as-advertised look at Rolison, who was drafted by the Padres in the 37th round in 2016, before going on to star at Ole Miss for two seasons (166 strikeouts in 160 innings). The Rockies drafted him with the No. 22 overall pick in '18. He has thus far profiled as a ¡°crafty lefty,¡± with a low-90s fastball, but good feel for its location and smart use of his secondary pitches.

Manager Bud Black said Rolison should eventually throw harder, which would make his curveball and changeup play better. Invitations to Spring Training and Summer Camp were designed for a jump-start.

¡°It's part of his progression, part of his growth, to hopefully get to Denver and pitch in the Major Leagues,¡± Black said. ¡°It was good to see him out out [Saturday] night on our mound, facing Trevor, Nolan, [Sam] Hilliard, [Matt] Kemp. I thought he threw the ball fine. I think there's more velocity in there moving forward.

¡°But this guy's a pitcher. This guy knows how to pitch, he can change speeds. He's got two secondary pitches that I think will play in the big leagues, he's got enough fastball. He's got a good head on his shoulders. We're learning more about the guy, what makes him tick.¡±

Last year¡¯s performance in his first full pro season (8-8 with a 4.40 ERA in 25 starts between Class A Advanced Lancaster and Class A Asheville) gave Rolison and the Rockies enough information to settle on a slight adjustment to his left plant foot that could help his balance and his direction toward the plate, which could push his fastball into the mid-90s.

¡°It¡¯s kind of a shift in weight in my balance, more in my heel, not my toe,¡± said Rolison, whose fastball velocity is around 90-91 mph, but it generally climbs the more he pitches. ¡°Several times, I got momentum going toward my toe, and it was taking me off the line that I need to be on, going straight toward the plate. Those are some things that we¡¯re working on in the sides and in the throwing program.

¡°From a young age, I¡¯ve always been taught command over velocity. I always knew the velocity is going to come. I work hard every offseason to build that arm strength. But first and foremost is the command part.¡±

All this was supposed to happen at Double-A Hartford. It would have been nice to have his Coors Field debut occur with packed stands, his family in attendance and in a game that counted.

But current circumstances led to Rolison getting a taste of the big leagues on Saturday.

¡°The mound was pristine,¡± Rolison said. ¡°Getting to pitch in a park like this, and especially getting used to the altitude and talking to the guys that have pitched here about different things to focus on with breaking balls, fastballs and other pitchers, it¡¯s good to be here and compete.¡±