Hockey players may be the toughest athletes in all of sports.

Every minute of every shift, they risk breaking bones, tearing muscles, or even losing teeth for the greater good. They don’t complain, they don’t whine and they certainly don’t cry. When they're injured, they’re stitched up and back on the ice in time for the next shift.

Talk about commitment and making sacrifices.

So what, if anything, could make these guys get even slightly emotional?

How about a ceremony celebrating their passion for the sport and their commitment to the teammates and city they played for?

Add some family and friends and that’ll do the trick.

On Monday, the Blues honored four of the greatest players ever to have the No. 7 stitched on their sweaters: Gordon “Red” Berenson, Garry Unger, Joe Mullen and Keith Tkachuk. The team held a pregame ceremony outside Scottrade Center before Monday’s game vs. Columbus to celebrate the careers of each player, helping to pay them back for the pride they exhibited while wearing the Blue Note on their chests.

And perhaps even more touching? All four players laced up the skates and stood at the blueline during the National Anthem before the game.

Unger couldn’t help but get a little emotional on Monday.

"I spent a fair amount of time here. I played a majority of my career in St. Louis," he said. "I got married when I was here and my kids were born here. I had an opportunity to fulfill a lot of my childhood dreams here. It was really a special time of my life."

Since their inception in 1967, the Blues have retired just six numbers: No. 2 (Al MacInnis), No. 3 (Bob Gassoff), No. 8 (Barclay Plager), No. 11 (Brian Sutter), No. 16 (Brett Hull) and No. 24 (Bernie Federko). Retiring a sweater is a time-honored tradition, and one that all four of Monday’s guests of honor might have received had they not all worn the same number.

So instead, the Blues opted to salute No. 7, giving each of them a unique painting and a jersey from the era in which they played. In addition, the Blues unveiled a banner featuring action shots from their playing days. The banner will permanently reside above the Suite located in Section 107 at Scottrade Center.

“We are always looking to add unique and special events for our great fans and this event undoubtedly qualifies,” said Blues CEO Mike McCarthy.

Berenson wore No. 7 from 1967-71 and ranks 12th all-time in Blues history in games played (519) while placing seventh in goals (172) and eighth in both points (412) and assists (240). He’s tied for second in game-tying goals (15). As a coach, he led the team to a 100-72-32 record.

Unger, the second player to wear No. 7 (1970-79), is the fourth-longest tenured Blue in club history. In 662 games, Unger ranks fourth all-time in goals (292) and points (575), sixth in assists (283), third in hat tricks (7) and game-winning goals (40) while remaining the club leader in game-tying goals (19).

Mullen wore No. 7 from 1979-86 and played 301 career games for the Blues. He ranks 11th all-time in goals (151), 20th in assists (184) and 13th in points (335). A 16-year veteran, he is one of seven players in team history to average over a point per game with the club.

Tkachuk was was the last player to wear No. 7 (2000-10) and retired last season. A five-time NHL All-Star, Tkachuk ranks 11th in club history in games played (543), fifth in goals (208), 13th in assists (219), seventh in points (427) and is tied for fifth in game-winning goals (29).

"I feel honored to be a part of (this). I've always loved the Blues," Berenson said. "(The No. 7) has been a good number, but it's really been a good memory for us to be part of the Blues. I think we all feel the same."

"(Wearing the Blue Note) didn't mean much at first, we questioned it," Berenson recalled. "But by the end of the first year, everything started to fall into place. There was no second-guessing of the team, the players, management or the uniforms. The organ playing 'When the Blues Go Marching In' was unbelievable. It made us a goal-a-game better every time we stepped onto the ice at home.

"(St. Louis) became a special place."

Monday’s game featured food, drink and merchandise specials for $7. In addition, a special silent auction featured autographed items from each of the former No. 7s.

"I feel pretty honored to be mentioned in the same breath as the other three guys," Tkachuk said. "It's a fun night. I'm taking it all in and I really enjoyed my time here."