But, the visit south brought him into contact with another Scot who is suffering at the moment, Old Trafford boss, Davie Moyes.
Lennon has been appalled at the level of personal attacks and cheap shots aimed at the man who succeeded Sir Alex Ferguson, including fans paying for an aircraft to fly over the ground today displaying a banner calling for Moyes to go.
He can empathise with his plight, and is convinced the Scot will get it right.
Lennon makes the point the four years he has been in charge of Celtic might never have got past season one, if people had not shown him patience.
He reflected: "I have a little understanding of what David Moyes is going through, but I can't second guess how he's feeling.
"Like all manager's job when you go through a rough period, it's a lonely place to be.
"What I'm not happy about just now is the way people are rounding on him. You don't mind constructive criticism, but it's when it comes to the point they're trying to humiliate him that it leaves a sour taste in the mouth.
"He deserves a lot more than that and should be treated with more respect."
Lennon knows only too well how bad it can get in this most public of positions.
"I can identify with it," he said. "The Kilmarnock day (in his first season) when we were 15 points behind and 3-0 down walking down the tunnel thinking 'Ciao. Sayonara. I'll get my coat!'. All those things go through your head.
"We were fortunate enough to turn things around and I'm pretty sure David will as well.
"He's got a big job on rebuilding the team. But it's the tacky criticism, such as the plane, that annoys me.
"A lot of people in football want him to do well, myself included."
Lennon cut his teeth in management in one of the most high-profile jobs in the country.
He had previously been linked with Hibs and Motherwell. But, asked if he feels he would have been better equipped if he had ben able to cut his teeth elsewhere, he replied: "Looking back on it, probably not.
"I feel I did an apprenticeship anyway. I had a year under Gordon Strachan, then a year with the development team.
"I remember speaking to Mark McGhee, and, when he left Motherwell, he put my name forward.
"I said I didn't know if I was ready yet. But he said: 'You never know if you're ready'."