The 38-year-old’s career at Tottenham Hotspur ended at the age of 22 due to injury.
He said he was considering pursuing a career as a maths teacher, sports physiotherapist or sports trainer before an inspirational talk with a club medic.
Speaking at a ceremony in Ipswich on Monday, McKenna said: “It made me realize that so often in our careers, so often in our ambitions, we are limited by our own perceptions of what is possible, by our own perceptions of what we can achieve
“At this point in my career, even becoming a community coach, a youth coach, would seem like an incredible achievement and would be my absolute dream.”
He urged the students to “walk towards their greatest goal.”
“If you have goals in life, if you have some things you’re not sure about, if you’re not sure, pursue your passion,” he said.
“Go with your heart, go with the one who means the most to you.
“Go with the one you love and chase him with everything you’ve got.”
McKenna took over at Ipswich Town in 2021 after leaving his role as first-team coach at Manchester United.
He returned Ipswich to the top flight for the first time since 2002.
Earlier this year the club and Suffolk University signed a three-year partnership agreement with a collective mission to inspire Ipswich and Suffolk pride.
McKenna said: “It feels fantastic, it’s a great honour.
“It’s a really important place for me now and I feel so embedded in the community here and of course Suffolk University is a big part of the community, so it’s a fantastic honor and one I’m really proud of.
“Both institutions have a big role in the community, and I think the connection with the university is really important to us.
“We have to keep trying and improving and innovating and developing in all areas and of course that’s also a great spirit of the university, so it’s an important relationship for us and we hope it will continue stronger and we can both continue to grow, and we can both continue to help the local community.”
He joked that he would make sure the players addressed him with his new honorary title of ‘doctor’ at club training this week.
And in a message to graduates, he urged them to “let your biggest failures be the ones that shape your character.”
“I believe that in those failures you show your true character and you show the people around you your true nature,” he said.
Meanwhile, Ipswich Town’s only professional player swapped her football kit for a dress when she graduated from Suffolk University.
Sophie Pesquet combined degree studies with her thriving professional football career and now has a first class BA (Hons) in Sport and Exercise Science.
The 21-year-old midfielder is now looking forward to focusing on her football at Ipswich, where she became the club’s first professional player in the summer of 2021.