The Swans have made enormous changes to their list over the past four years, either drafting or trading for Josh Kennedy, Dan Hannebery, Shane Mumford, Luke Parker, Nick Smith and Sam Reid.
All are 26 years or younger and all are now major contributors to a side that blossomed unexpectedly quickly last year to snare itself a premiership.
Mitchell was taken with pick 21 in the 2011 NAB AFL Draft via the father-son rule, with his father Barry playing 170 games for the club from 1984-92, and has conquered some knee issues to force his way into the side.
With Kurt Tippett to be added to the forward line after the bye and Gary Rohan making good progress from his broken leg, the Swans' stable of young talent is in place for years to come.
A prolific ball winner who relishes hard, contested football, Mitchell has played the past seven games in the reserves and forced the coach's hand.
"He's a very determined young man and very much a competitor, which is an attribute we love and it's a really good start," coach John Longmire said of the midfielder, who turns 20 on Friday.
"He's a very good strong contested ball player and hopefully adds to that mix that we've got with Josh Kennedy and Luke Parker and Hannebery and those type of players that add some more depth to our midfield group.
"We always knew when he was able to get a run at it physically that he was a good enough player to warrant playing senior football.
"He's strong and physically able to match it with them and he doesn't shirk the contest.
"It was just about getting some miles in his legs and once he did that, his football started to really improve and his training standards improved and he got to the stage of playing his first senior game."
Mitchell will need to have a level head for his debut, which will come in front of a sold-out SCG crowd against fellow top-four hopeful Essendon.
The powerfully built midfielder knows it will be a huge occasion.
"It's a really big game," Mitchell said. "I think the game might be sold out and it's going to be a big challenge for us.
"Essendon have had a great start to the season.
"I'm just grateful for the opportunity and looking forward to trying to contribute and hopefully get a win."
Barry Mitchell was inducted into the Swans' Hall of Fame in 2011 following a career that included leading the club's goalkicking in 1988 and an All Australian guernsey in 1991.
"His father Barry obviously had a great career with the Sydney Swans," Longmire said.
"Now it's Tom's turn."
James Dampney is a reporter for AFL.com.au. Follow him on Twitter: @AFL_JD
