Diontae Spencer breaks away from the Calgary Stampeders defense and scores a vital touchdown off the punt return for the Ottawa Redblacks. (0:39)

ENGLEWOOD, Colo. -- The Denver Broncos could open the regular season with a 27-year-old rookie who stands all of 5-foot-8-inches tall -- maybe -- catching punts. Maybe kickoffs, too. A guy who has spent the past four years in the Canadian Football League and the summer with the Pittsburgh Steelers.

But if Diontae Spencer can unpack, learn fast and show enough in a week's worth of practices, he could be the Broncos' return man come Monday Night Football at the Oakland Raiders in Week 1.

Or as Broncos coach Vic Fangio said earlier this week after seeing Spencer in all of one workout: "I think we're planning on it."

"It's a big opportunity, I'm just blessed to be here," Spencer said. "This is my first time in Denver. I'm just ready to get here, work, get to know everybody, my teammates, coaches and just play football."

Diontae Spencer spent the past four years in the CFL and the summer with the Steelers, but after a few practices he looks like Denver's return man. Christopher Hanewinckel/USA TODAY Sports

The Steelers waived Spencer on Saturday when rosters leaguewide went to 53 players, and he arrived in Denver Sunday night. By Monday afternoon he was already catching most of the punts and Fangio was already acting like he had his fingers that crossed Spencer could be a solution. When asked early in camp about the team's punt returner, Fangio had said "We don't have one right now.''

The Broncos haven't returned a punt for a touchdown since Omar Bolden ran one back 83 yards against the Indianapolis Colts in November 2015. The team hasn't returned a kickoff for a score since 2013. Last season the Broncos' top two punt returners -- River Cracraft and Adam Jones -- averaged 3.3 and 2.5 yards, respectively per return.

Enter Spencer, who certainly fits the profile of a fall-through-the-cracks player. He's undersized and played at a non-Power 5 school (McNeese State). He was not selected in the 2014 draft despite a game during his senior year against Stephen F. Austin when he returned two kickoffs and a punt for touchdowns. He wasn't signed as an undrafted rookie, either, in the days following that draft. Instead, his first attempt at an NFL rookie year in '14 consisted of a week's worth of practices with the Chicago Bears and a stint with the Rams when he was added in May and then cut in July.

So, Spencer went to Canada, land of three-down football on a 110-yard field with 20-yard end zones, as one season turned to two, two to three and finally four.

"I never thought it would take four years, but each year I always thought I had the opportunity and that window was always opened for me so it's just -- I feel like right now it's just the perfect time," Spencer said.

Spencer played 57 games over the past four years in the CFL, including three years with at least 71 receptions. He set several team and league records along the way -- he spent two years in Toronto and two years in Ottawa -- including a single-game mark of 496 all-purpose yards against Hamilton in 2017 (133 yards receiving, 165 yards on kickoff returns and 169 yards on punt returns).

With the Steelers in the preseason, Spencer had the team's longest run from scrimmage, longest punt return and longest kickoff return. And if Spencer could somehow contribute in some way on offense or return kickoffs for the Broncos, it would be a tidy little bonus.

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What the Broncos really want, however, is for Spencer to be their punt returner, to be more than the well-he-caught-it guy.

"He's got a lot of experience doing it," Fangio said. "He's quick, fast and he's a seasoned returner."

Spencer returned a whopping 191 punts in his four CFL seasons, including 82 in 2018. To put that into perspective, Cracraft led the Broncos with 12 punt returns last season and the Broncos had 30 as a team.

Tarik Cohen was the only player in the NFL to have more than 23 punt returns last season, finishing with 33 for the Bears.

"[I want] to put the offense in great field position and if I can score, it'll happen," Spencer said. "For me it's all about going out there, letting the game come to me and just playing fast. It's going to be a lot of emotions, but that's a part of being a pro. I'm just excited to get out there ... it's been a long time coming."