This is the time of year when all NFL teams are putting their rosters together for training camp.

And one of the most exciting events of the calendar year, the annual NFL Draft, has just concluded.

But we have to keep in mind that all rosters are also built from the inside and out — that is, with the inclusion of a group of players not drafted in the seven rounds. This group is overlooked in the frenzy of taking the best prospects available in rounds one through seven.

But history is full of players not drafted at all, and Denver Broncos history is no exception.

Our list of undrafted college free agents includes some who played elsewhere previously, some who continued their careers somewhere else after Denver and many who played their entire pro careers in the Mile High City.

But all are examples of guys who made it after some, or even most teams said they could not. Every team has these players, and I thought we might take a look at some of the Broncos' most prominent examples of talent at one time overlooked.

From 1960 until the present, the Broncos' roster has always had someone who was a good player, even a star, despite not having been taken in the college draft.

Due to my own age and knowledge, I could write vast summaries of these players, but for now we will just make more cursory mentions.

For the Broncos, these players include current players, Pro Bowlers, Ring of Famers and even a Hall of Famer.

In fact, for Denver, you can go all the way back to the beginning, when the team had two future Ring of Famers who had not been drafted: Gene Mingo, who had played only for the United States Navy in service ball after high school, and Lionel Taylor, who had played one year as a free agent linebacker for the Chicago Bears before becoming one of the great receivers in pro football history with the Broncos.

The current Denver roster includes cornerback Bryce Callahan, wide receivers Tim Patrick and Diontae Spencer, linebacker Malik Reed, defensive lineman Mike Purcell, placekicker Brandon McManus, wide receiver/quarterback Kendall Hinton, cornerback Essang Bassey, quarterback Brett Rypien, linebacker Alexander Johnson and offensive lineman Austin Schlottmann.

One of the first things players do when they enter a locker room is take off their civilian clothes and put on the same uniform. At that moment, newspaper clippings, previous publicity, signing bonuses and contracts all mean far less than what happens on the field. The guys who run the fastest, make the most plays and catch the coaches' eyes with consistency find their way to the roster.

The NFL is a meritocracy. Nobody cares about potential as much as performance.

Just recently, undrafted free agent Phillip Lindsay signed with Houston after three successful seasons in Denver.

But he is not the only undrafted Bronco free agent who went on to another club.

Pro Football Hall of Fame cornerback Willie Brown played four great seasons in Denver before being traded to the Raiders, and he actually teamed up with another former Broncos free agent — Nemiah Wilson — at cornerback for the Raiders when they became Super Bowl champions.

Wendell Hayes was an outstanding free agent running back for the Broncos who also became a world champion, in his case with the Kansas City Chiefs, after moving on from Denver. In fact, Hayes was coached by future Broncos General Manager John Beake when Beake was a young assistant coach on the Kansas City staff.

Longtime NFL offensive lineman Ben Garland, a product of the United States Air Force Academy, began his pro football journey as an undrafted free agent in Denver.

More recently, star cornerback Chris Harris, Jr. went to the Los Angeles Chargers as a free agent after a lengthy stay in Denver.

Free agency today is such that players move on, but some stayed here for the duration of their careers and became franchise legends.

Ring of Fame wide receiver Rod Smith was undrafted and was a vital cog in our back-to-back Super Bowl champion teams, eventually becoming the team's all-time receiving leader. And while not as prominent as Smith, tight end Dwayne ("House") Carswell and defensive end Harald Hasselbach were on those world-championship teams as well. Neither was drafted after college, but both had long careers in Denver.

Hasselbach in fact is one of 13 players to play for Super Bowl champions and on a Grey Cup championship team in the Canadian Football League.

Wide receiver Steve Watson and defensive tackle Greg Kragen were key players on our 1980s AFC championship teams, along with linebacker Jim Ryan, all of whom joined us as undrafted free agents.

I remember well when our personnel department cleaned out the files by inviting everyone to a gigantic free agent tryout camp — think of the "Star Wars" bar scene applied to football, as far as a wide range of characters was concerned.

There were 478 players present that day, and when it was over Rich Karlis was offered a contract and became a very popular and successful kicker for the Broncos.

Back in the 1960s the Broncos didn't have much, but they had free agent undrafted free agent offensive linemen Sam Brunelli, Larry Kaminski and Jerry Sturm.

In fact, our All-Time Top 100 team includes Sturm and Kaminski, as well as fellow undrafted free agents Rod Smith, Lionel Taylor, Mingo, Carswell, Harris Jr., Kragen, Bob Swenson — a great linebacker on our Super Bowl XII team — linebacker Jim Ryan, wide receiver/punter Billy Van Heusen, Matt Lepsis, and one of the greatest players of all time, fullback Cookie Gilchrist.

Taylor was recently named by the Talk of Fame Network's AFL "Call to the Hall" committee, of which I was a voter, as one of the 10 greatest American Football League players not already in the Pro Football Hall of Fame.

Sturm had the longest career on the offensive line, 15 years (NFL and CFL careers combined), of any Bronco in history, having played six seasons in Denver, and was twice named an AFL All-Star.

We even had a former head coach, Dan Reeves, who was undrafted out of South Carolina and had a great career as player and coach. Reeves, like many others, ought to be in the Pro Football Hall of Fame for his playing and coaching body of work.

Are there others?

Yes, there certainly are, but this is just a look at some of the most prominent players, those with the longest and most successful careers in pro football.

These stories are a reminder to us that rosters are fluid and built in many ways.

The draft is huge, a cornerstone of roster building in the NFL. But sometimes ...

Sometimes the best players come after the draft is over, when teams are signing guys that they liked in college, but maybe not quite enough to select in the draft.

Sometimes they are players who just will not give up, who travel from tryout to tryout in city after city, believing in themselves above all else.

Every player has a story.

Sometimes it starts with not being drafted at all.