(Courtesy Comcast SportsNet) (Courtesy Comcast SportsNet)

Like many budding sports broadcasters, Chick Hernandez grew up dreaming of a career in play-by-play. He even had a makeshift lab: the upper deck of Baltimore’s Memorial Stadium, where a teenaged Hernandez and a high school friend would provide complimentary commentary for everyone seated in their vicinity.

“For two innings, people thought we were pretty cool,” Hernandez recalled this week. “By the fourth inning, they wanted to shoot us.”

Still, Hernandez continued to chase that play-by-play life in college, serving as WMUC’s voice for Maryland basketball the season after Len Bias’s death. But professional play-by-play jobs are limited, and there are far more opportunities as a sports anchor, and Hernandez interned for Glenn Brenner and James Brown, two anchoring icons. And so Hernandez — a staple at Comcast SportsNet since the network’s first day — built his career as perhaps Washington’s most respected sports anchor, filling his play-by-play jones with occasional college football and basketball assignments.

A few weeks ago, though, he learned that a scheduling conflict meant the Redskins needed a play-by-play voice for their third preseason game, and that he was the choice.

“And I went ‘Hoo-lee cow,’ “ Hernandez said. “I don’t know how my name came up, but it came up, and I’m grateful.”

So instead of his usual perch on the CSN set Saturday afternoon, orchestrating the network’s pre- and post-game shows, Hernandez will instead be inside FedEx Field, calling the Redskins-Bills game with Joe Theismann. NFL Network is also broadcasting the game, so Hernandez’s call will reach a national audience, which demands insight on both teams. The starting quarterbacks might be Rex Grossman and Kevin Kolb, but this is a big-time assignment, with a big-time reach.

“I haven’t had butterflies in my job for a long time, but they are beginning to grow,” Hernandez joked earlier this week. “I feel like one of the players on Monday Night Football: I know everybody’s going to be watching.”

And circumstances will make this a particularly challenging first pro-sports assignment. For one thing, teams have not yet made preliminary cuts, so instead of learning about 26 or 28 college basketball players, Hernandez must prep for 180 NFL players. The quick turnaround from Monday night’s Redskins game means Mike Shanahan is apt to turn to reserves earlier than normal, while the injuries to Kirk Cousins and EJ Manuel nixed the game’s most obvious storyline.

Hernandez was up past 3 a.m. on Thursday morning preparing, and planned on another late night Thursday. He isn’t normally early to work, “because I don’t like sitting around,” he said, but he’ll make an exception this time, and plans on arriving at FedEx Field “earlier than for any job I’ve ever been to.”

As for the broadcast itself, Hernandez faces an unusual challenge. As the host of CSN’s pre- and post-game shows, he has latitude to be critical of players and decisions. As the play-by-play man for the team’s preseason broadcast, he will strike a different tone.

“For me, calling the game, my job is to call the action and set Joe up for the analysis, and that’s what I’m going to stick to,” he said. “I’ve got a football guy to draw out, and it won’t be very difficult, as we all know, to draw Joe Theismann out. My challenge is not to lob out softballs, but to elicit more analytical stuff that the viewer will find interesting. And I don’t care what anybody says about how much Joe talks; if you listen to what he says, he’s spot-on.”

Hernandez said he hopes Saturday’s broadcast might afford him other play-by-play opportunities in the future, and that he still would like to move into that genre on a more regular basis. Which doesn’t mean he won’t miss his old gig on Saturday. Rob Carlin will host the pre- and post-game shows; he’ll throw to Hernandez inside the stadium for a pre-game hit, which the latter said will be “surreal.” He even offered to come down to the set afterwards to participate in the post-game banter. His offer was declined.

“No, just do your thing,” he was told. “Enjoy the moment.”