to the ice wearing his normal #7 jersey, which he had worn since breaking into the league in 1979. He skated over to the Hall of Famer, took off his #7 jersey and handed it to Esposito in what was referred to as Bourque's "surrendering" of #7 to Esposito. Underneath was a jersey numbered 77, which would become as associated with Bourque as #7 had been with Esposito in Boston. Bourque's new jersey number would eventually join Esposito's in the rafters of TD Garden, as the Bruins retired his #77 following his 2001 retirement. In rare cases, a number may be retired because of the player's endeavors in other fields. For example, former college football star Gerald Ford's number 48 was retired by the University of Michigan football squad by virtue of his future career as the 38th President of the United States. Teams also take numbers out of circulation without formally retiring them, though it is generally understood that those numbers will never be issued again. For example, the Pittsburgh Steelers have only officially retired three numbers: Ernie Stautner's #70, Joe Greene's #75 and Franco Harris' #32. However, they have not reissued the numbers of several of their greatest players since they retired, and it is understood that no Steeler will ever wear them again. For example, Greene's #75 had not been reissued since Greene retired in 1981. Similarly, with the exception of a pair of quarterbacks in the mid-1980s, the Green Bay Packers have not re-issued Paul Hornung's number 5 since his departure from the team following the 1966 season. The Dallas Cowboys do not officially retire numbers, but it is generally understood that Roger Staubach's #12, Bob Lilly's #74, Troy Aikman's #8, and Emmitt Smith's #22 will never be issued again (though the Cowboys have occasionally used Lilly's 74 in the preseason). Additionally, after Peyton Manning was released by the Indianapolis Colts, owner Jim Irsay stated that no Colt will ever wear Manning's #18 again, though it was not officially retired until 2016. After his departure from the team in 2004, the Lakers removed Shaquille O'Neal's #34 from circulation, only officially retiring it in 2013. Some teams either formally or informally take a jersey out of circulation when a player dies or has their career ended by serious injury or disease. For instance, between 1934-2016, the Toronto Maple Leafs only retired a player's number if he experienced