When it comes to finding a comparable in other sports, NFL quarterback is often cited as the closest thing to being an NHL goalie because of the impact, scrutiny and pressure involved, and the individual, sometimes even solitary, nature of the positions.

Thanks to Jake Allen and the St. Louis Blues, the comparison now also extends to backups.

Just as football quarterbacks are sometimes asked to mimic the next opponent in practice as part of the scout team, Allen was cast as Tuukka Rask to help the Blues prepare for the 2019 Stanley Cup Final against the Boston Bruins and their Finland-born goalie.

Allen, the backup to St. Louis No. 1 goalie Jordan Binnington, went on the ice early with Blues goaltending coach David Alexander to shoot footage of his Rask impersonation, which was used in the pre-series breakdown of the Bruins' No. 1 goalie.

"I'd try to act like Rask, skate like Rask, and try to imitate what he does that is different," Allen said. "Just the way he holds himself and how low he looks, but his chest is forward and a lot of little things he does specific to his game. We'd go back on all the goals he let in, find tendencies, and try to imitate them to show guys a few clips that Dave could voice over and I'd be in net. ... We broke it down in very layman's terms, so I think everyone understood."

Video: STL@EDM: Allen robs Chiasson while falling to the ice

Goaltending coaches have long been responsible for providing a scouting report on opposing goalies, and they can become increasingly important in the Stanley Cup Playoffs, when any identifiable weaknesses can be targeted repeatedly over a best-of-7 series. St. Louis forwards praised Alexander for the depth, detail and effectiveness of his presentations on how and where to score on opposing goalies, but Allen's demonstrations added a new twist.

It's hard to find examples of it being done before. One goaltending coach remembered asking his backup to stay close to the goal line in practice to mimic an opposing goalie who played deep in the crease, and another asked his backup to stack the pads in practice heading into a playoff series against Dominik Hasek. During the 2010 Vancouver Olympics, United States goalie Tim Thomas was spotted imitating Martin Brodeur's unique style in practice before a game against Canada, but for the most part, scouting reports on opposing goalies are limited to video breakdowns.

Having Allen channel Rask for the videos appears unique, letting the Blues control the framing of an easily relatable visual addition to the usual trends and statistics for St. Louis shooters.

"Never seen anything like it," center Brayden Schenn said. "I've been in playoff series before, and you see where the tendencies are to score, but they've never broke it down quite in depth like that before. It just kind of gives you a different way of looking at it because Tuukka plays a little different than what most shooters are used to seeing. Obviously, he's still a great goalie, and you have to try and find ways to break a guy down like that. It's credit to David Alexander and Jake working together and doing what it takes to try and win the Stanley Cup."

Allen said the idea was born out of conversations about differences in the first three goalies the Blues faced in the playoffs: Connor Hellebuyck of the Winnipeg Jets, Martin Jones of the San Jose Sharks and Ben Bishop of the Dallas Stars. They had plenty of experience against each of them in the Western Conference, but less so Rask, whose style has some unique quirks.

Video: PHI@BOS: Rask turns aside Provorov on the doorstep

"You're looking at guys that play completely opposite styles of game, sizes, techniques, gear," Allen said. "So, I said, 'Why don't we try to implement something where we can show the boys what this guy does compared to that guy and ways we can potentially score?' The optical illusion each of those guys have, that they look bigger than they are in certain positions, is different in the net and I think that's what we were trying to create from an understanding standpoint for the players. If it caused a goal or two in the playoffs, then we did our job."

No Blues claimed it was the reason Rask finished the Cup Final with a .912 save percentage in seven games after having a .942 save percentage in 17 games through the first three rounds, but it didn't hurt.

"It's not like it made the series but it helped us for sure," said center Ryan O'Reilly, who was awarded the Conn Smythe Trophy as playoff MVP after St. Louis defeated Boston in Game 7. "It helps gets you in the mindset of the way the goalie is moving, which is a good thing."