Celtic boss Neil Lennon revealed he expanded his football education with a reconnaissance trip to Lille as he prepares for a tough French exam.
The Northern Irishman was in his first spell as Hoops boss when he took the opportunity to look over the set-up at the French club after they had won Ligue 1 in 2011.
The Scottish champions take on Les Dogues at the Stade Pierre-Mauroy on Thursday and Lennon spoke about his admiration for Lille, who are behind Ligue 1 leaders Paris St Germain only on goal difference.
The former Celtic captain, whose side lost 3-1 to AC Milan in their Group H opener at Parkhead last Thursday night, said: "When the group came out I was delighted to see the quality of opposition that we got.
- Lennon hits back: 'There's no justification to sack me'
- Celtic revenue falls by 16 per cent
- Dalglish backs Lennon amid Celtic's winless run
"Lille have been a very good, top-of-the-range French team for a long time.
"I actually did a club visit there, a few years ago, when they won the French league and had a look around the place. The stadium was just about to be finished.
"Our previous fitness coach, Gregory Dupont, was working there and I asked if I could go over and have a look around for a few days so I did and it was great.
"I was there for three or four days, it is a beautiful town.
"I was looking at the training facility and the stadium, which is finished now. Gregory has gone on to work with the French national team at the World Cup and is currently with Real Madrid.
"It was a good experience and so it is a club I am semi-familiar with. Back in those days you had Eden Hazard there, and Joe Cole, they recruit well and have good strength in depth.
"So, I know a lot about the club and the culture of the club and what they do at academy level as well. So it's no surprise to me to see them doing so well.
"They have a strong team again and started the season very well. It might be a difficult time to play them but it is a real good challenge for us and one we are looking forward to."
Lennon revealed French striker Odsonne Edouard and Israel midfielder Nir Bitton are back in the Celtic squad after missing the last three Hoops matches due to contracting Covid-19 on international duty.
Israel defender Hatem Elhamed, who also caught the virus while away with his country, is on the way back but has remained in Glasgow.
Greek goalkeeper Vasilis Barkas, who missed Sunday's 3-3 draw with Aberdeen at Pittodrie with a back problem, has made the trip to France.
Lennon said: "Elhamed has stayed behind. Bitton and Edouard have travelled.
"They are up to speed to play a part in the game. Whether we start them or not, that is something that we have to assess.
I don't think we can start the both of them but they'll definitely be available to play some role in the game.
"Nir had it pretty heavy in terms of how much it took out of him. Physically he is getting there.
"Odsonne, it's not been too bad for him. He seems pretty strong now, he has had a few days longer than Nir in terms of training with the boys and training on his own.
"Elhamed seems to have recovered quite well and hopefully he will be available at the weekend.
"Vasilis' back seems to be OK, he has an ongoing shoulder issue but nothing too strenuous."