Quite often team's employed assistant equipment trainers. Not because the full time equipment trainer needed help necessarily, but to play the role of practice goaltender. That way the goalie to get his rest before the game while shooters could sharpen their skills with a goalie in the nets.
Everyonce in a while a goalie would get hurt during the game. A number of times the assistant trainer/practice goalie would be called in to finish the game. More often than not it would be that trainer's only shot at NHL action.
This happened on the night of October 21, 1961. The New York Rangers were in Detroit playing the Red Wings. In the second period, Rangers goalie Gump Worsley got injured and couldn't continue. Because the practice goalie rarely travelled with the team, the Rangers asked permission to use the Red Wings practice goalie in order to finish the game. The Red Wings agreed.
The practice goalie that season was Dan Olesevich. He stepped in and played 29 minutes. He allowed just 2 goals and earned a tie against the team that gave him his paycheck.
Unlike a lot of practice goalies who stepped in for a few minutes of action, Olesevich had a decent background as a goaltender. He played for the Hamilton Tiger Cubs for 4 seasons starting in 1953. He however was basically a spare goalie there too. He did jump to the pro ranks in 1958 when he split the season in the EHL and NOHA. He played in 56 games that season.
However Olesevich realized he wouldn't likely make a living as a goaltender, so when the Red Wings offered him a position as trainer/practice goalie in the summer of 1959, he retired as an active goalie and began working for the Wings.