GREEN BAY, Wis. -- A former college basketball player, a two-year practice squad member and a would-be gym teacher walk into the Packers locker room ...

No, this isn't the beginning of a joke. It's the story of Michael Clark, Reggie Gilbert and Emanuel Byrd.

And it could be an infusion of Packers playmakers, based on what each showed at the end of last season.

Clark was a 6-foot-6 forward at Saint Francis University in Pennsylvania who decided his calling wasn't in basketball but rather as an NFL receiver. Gilbert is an outside linebacker who couldn't find his way to the roster for nearly two seasons. Byrd is a tight end who was about to take a job as a physical education teacher when the Packers called him back in November.

All three entered the NFL as undrafted free agents.

All three were promoted from the practice squad to the 53-man roster for the first time last December.

And all three made the kind of impact that aroused the Packers' interest going into the offseason.

Former college basketball player Michael Clark made four catches for 41 yards in his two December games last season. Jeff Hanisch/USA TODAY Sports

Yes, the Packers bolstered their receiver room with three draft picks -- J'Mon Moore (fourth round), Marquez Valdes-Scantling (fifth) and Equanimeous St. Brown (sixth) -- which will make it tougher for Clark. But they didn't draft an outside rusher until the seventh round, and they didn't draft a tight end at all, which not only should help Gilbert and Byrd, but also could be taken as a sign of confidence in them.

Gilbert looks like the most promising prospect of three. He spent all of 2016 and the first 15 weeks of the 2017 season on the practice squad. It wasn't until Dec. 22, the eve of the penultimate game of the season against the Minnesota Vikings, that he got the call to the active roster. All he did was record a team-high three quarterback hits. In the finale at the Detroit Lions a week later, he added his first career sack.

"It wasn't like an I've-made-it moment," Gilbert said this week. "But it was, 'OK, all your hard work is starting to pay off, so you've just got to stay the course.'"

No one would anoint him as the next Reggie White, but it's not out of the question to list Gilbert as the Packers' No. 3 outside linebacker, behind Clay Matthews and Nick Perry on the depth chart. The Packers have no intention of re-signing Ahmad Brooks, who recorded just 1.5 sacks in 12 games last season for $3.5 million, and their other returning outside linebackers include underachieving 2016 third-round pick Kyler Fackrell (five career sacks in 29 games), 2017 fourth-round pick Vince Biegel (no sacks in nine games) and waiver wire pickup Chris Odom (no sacks in seven games).

Because Gilbert spent only two games on the 53-man roster last season, he was eligible to participate in last weekend's rookie camp, where he caught the eye of coach Mike McCarthy.

"I'll tell you what, Reggie Gilbert looks great," McCarthy said. "I was kidding with him yesterday; I said if he keeps running around the way he's doing in pass coverage, I'm going to move him to tight end. It's incredible what he's done in his time here. You talk about a guy that has done everything and has taken advantage of every resource that's been available to him. I mean in my mind, he's already taken the second-year jump. It's great having him out there. He's a great example for these young players. He's a great example for the free agents."

Emanuel Byrd had a pair of catches in his one game with the Packers last season and should compete in a wide-open tight end competition behind Jimmy Graham. Mark Hoffman/Milwaukee Journal Sentinel via USA TODAY NETWORK

Byrd also took the field for rookie camp because he played in only the regular-season finale, when he had catches for 31 yards (including a 29-yard catch-and-run, during which he lost his left shoe). Byrd didn't even join the Packers until the second week of training camp last summer, and after he was released at the end of the preseason, he was out of football until the Packers brought him back to the practice squad in Week 9.

"It meant the world to me," Byrd said shortly after last season. "When I was home, even though I got cut, I was believing. I was still working out, still going to the gym every night and trying to stay motivated and keeping the faith at the same time. Knowing I still had my degree, so I was still looking for work. It meant everything. Words can even explain what it meant. Never take it for granted. Every day I come in here, just to be around the guys in this locker room and this organization means so much more to me than people would know. I try to carry myself in manner and work hard, even harder just knowing these opportunities really don't come by. They're rare, especially being in the position I am."

The tight end situation is wide open behind Jimmy Graham, who was signed this offseason to be the starter. Veteran Lance Kendricks also returns, but the Packers didn't draft any tight ends. Byrd's biggest competition will come from another practice squad player, Robert Tonyan, plus undrafted rookies Kevin Rader (Youngstown State) and Ryan Smith (Miami of Ohio).

Clark played with Byrd at Marshall, where Clark transferred and played one year of football after he gave up basketball. Clark is the tallest receiver on the Packers' roster, and he showed off his basketball athleticism in training camp last summer with several days' worth of eye-catching grabs. He made four catches for 41 yards in his two games in December. Clark could not participate in last weekend's rookie camp because he was on the 53-man roster for five games, even though he appeared in only two.

"I knew since I quit basketball this is where I wanted to be at," Clark said late last season. "It feels like forever to get to this moment. I knew what I wanted -- not exactly Green Bay Packers, but I wanted to do one year of college football and I wanted to get out. That's what my goal was. If you're not confident in yourself, I wouldn't be here. Stuff like this doesn't happen by accident. I had confidence in myself, I knew I could do it, and that's what I did."

And there's a chance Byrd, Clark and Gilbert could do it again.