In a year when the Broncos are touting one of their most promising rookie classes in a long time, it’s an undrafted rookie running back who made the biggest impact on day one of training camp.

Phillip Lindsay, who the Broncos signed as a free agent out of Colorado, put on a show today for over 3,000 fans at Dove Valley.

The biggest highlight? A 50-yard touchdown reception where he put Brandon Marshall on skates and took it the distance.

The most impressive part of this is he’s already getting run with the first team. The coaches must have seen something out of Lindsay at mini camp to justify giving him reps with the big dogs this early. But hey, it’s working.

And he’s looking especially saucy in the process.

It’s obviously really, really early, but Lindsay seems like one of those undrafted free agents of destiny that is on a crash course for the 53-man roster or the practice squad to start the season.

It was the full trifecta for Lindsay today — running, receiving, and returning. The more ways you make yourself useful, the better the chance you have of sticking around. I don’t know what he’s like as a pass protector in the NFL yet, but if he’s decent enough at it you get the feeling he’s a shoe-in.

He’s got some pretty serious competition at running back, though. Devontae Booker and Royce Freeman are locks to make the team, and DeAngelo Henderson came on a little bit at the end of the season after having a strong preseason.

There’s also David Williams, who feels almost like an afterthought compared to Lindsay despite being drafted in the sixth round, but it looked like he had a solid day as well. I’m sure if he had a name that wasn’t so fantastically generic, we would be talking about him a little more. Even going by Davey Williams would be a huge upgrade, but I don’t want to tell him how to live his life.

It’s a bit of a mystery why Lindsay wasn’t drafted in the first place. He had a stellar career at Colorado and ran a sub 4.4 40-yard dash at CU’s pro day before the draft. It might just be that scouts are dumb and think size really matters in a running back despite that clearly not being the case (Darren Sproles, Tarik Cohen, C.J. Anderson). We’re living in the Stone Age, folks, and the Broncos got themselves a gem because of it.