Jamie Carragher and Gary Neville are famous for their disagreements over the years and this week's Monday Night Football featured one of the liveliest debates to date.
The Sky Sports duo crossed swords over Unai Emery's approach at Arsenal and whether or not he needs to adapt following Saturday's 3-2 defeat at Chelsea.
Carragher insisted he doesn't currently have the right players to start attacks from the back, play a high defensive line or press from the front - and he argued he needs to mix things up in the short-term.
However, Neville drew on his experiences as Valencia manager and argued Emery should stick to his principles, no matter what.
Hit the video above to see the debate in full or read on for the condensed highlights...
CARRA: I think the manager has to adapt. Not throw away all his principles, but defend a little bit deeper. Has he got the players to press from the front? He hasn't got the pace at the back. Has he got a goalkeeper who can play out? I just think that to get through to January he has to adapt.
NEV: I think it's ignorant to suggest he has to adapt.
CARRA: Is it not stubborn from you to say that?
NEV: No. He has had six weeks to work. Unai Emery has been a coach for 10 years and has been successful. He has his idea and the players have to adapt to him. He has to find out over this first season which players can adapt to him and which players can't. Of course he will lose games. In the first season there will be some pain for Arsenal in this transition they are going through. I think it's dangerous to adapt.
I know this from my biggest learning in Valencia. I set off on a path of what I was going to do and didn't get results. The minute I started to adapt and take people away from my idea and do things different, I threw away the previous three or four weeks of work I'd done.
If he starts to work on one idea of playing out from the back, but then says knock it long, you start to get confusion in players' minds. I saw Sam Allardyce's comments on the radio, but Unai Emery is not trying to get eight points from five games to avoid relegation. He's trying to build a team to win the title. The last thing he should do, in my experience, which was a bad one, is change and adapt because his players will walk all over him.
CARRA: I didn't expect Arsenal to win these games, all I'm saying is the things I saw - trying to play out from the back, putting the keeper under pressure - why do that? Why play a high line when Mustafi can't run? Are we saying top-level players in the Premier League cannot adapt?
I'm not saying play it long. Maybe if they can't play it long, chip it to the full-back as Chelsea did on the second goal. You say managers shouldn't adapt, but three or four years ago we lauded Arsene Wenger when he went to Manchester City and changed his plan and got a great result. Do you expect every single team to play exactly the same way, no matter where they go?
NEV: No, but since that point a big change has happened in football coaching and in education. If you've got children at home you set standards of how you want them to behave. If they start to not do it and you let them get away with it they will walk all over you.
Pep Guardiola, Jurgen Klopp and Mauricio Pochettino don't have a plan B, they make plan A better. That is a different way of looking at it than we were used to. I played in a team that could counter-attack, go long or keep possession - we adapted during games. It's different now.
CARRA: But you've criticised people on this show for not having that plan…
NEV: We've never criticised Sam Allardyce or anybody for their style. We've always appreciated different styles. We've never asked a manager to change his style and you're asking him to change his style.
CARRA: I'm not asking him to change his style.
NEV: You are.
CARRA: I'm asking him to adapt and not leave himself in situations. Seven or eight times in that game they could have conceded a goal.
NEV: After five weeks?
CARRA: Hold on, I haven't finished…
NEV: Jamie's little PowerPoint that he's done here is lovely.
CARRA: You should have taken it to Valencia…
NEV: Goalkeeper comfortable on the ball? If Petr Cech isn't comfortable then he will bring [Bernd Leno] in. Start attacks from the back? If they can't he will bring new defenders in.
NEV: Hang on a second. The high defensive line? Pochettino does it, Guardiola does it. If he can't do it then he will get Mustafi out and bring somebody else in. Press from the front? If Ozil won't do it then he will get him out.
CARRA: That's not what we're talking about.
NEV: Don't change your ideas. This is the idea that all football mangers now want to go to.
CARRA: Yes, you're saying he's going to get these players out. I'm not saying his idea is wrong - it's what the best teams in the country do - but right now there's nobody in that teams that tick those boxes. You're talking about a lot of pain and the idea of a four or five-year contract, but what you were saying before about how you bring your children up is an Academy coach's way of thinking. Emery has got to get results. It is Arsenal Football Club. They should be A*, graduating for university people at that club.
NEV: In the first year they will be working it out, implementing his ideas and they'll be fifth or sixth. Next year they should be challenging for the top four after three transfer windows. The year after he should be moving up towards first, second or third.
My view is this is a three-year project to try and get his ideas into the players. The last thing he should do in the early phase is lose control of the dressing room by adapting and taking away his principles.
CARRA: Will he get three years? He'll have to get results. He'll get 12 months and he'll start the next season. I don't think Arsenal are going to sack Emery and they shouldn't no matter what. But I can't believe the idea that we can't ask the top-level people in the Premier League to adapt in a football game. You're telling me you can't give footballers certain other messages and they can't understand football that much.
NEV: Walk into a dressing room for four or five months and try and do it. You'll find the difficulty of trying to tell players three or four different instructions for the same role.
CARRA: The way we grew up… you can't coach players like that no more?
NEV: It's different! You've got to adapt.
CARRA: Why's it different?
NEV: We've got to adapt as coaches, not the players! The players have changed and education has changed. Young people have changed.
CARRA: You sound like the Education Secretary!
NEV: You sound like a prehistoric old man!