Two holding players with one ahead? A flatter midfield three? A diamond? Debate about the best midfield formation for Man Utd is the hot topic right now - but Jamie Redknapp says that issue is "irrelevant" unless the players commit to their tasks for Ole Gunnar Solskjaer.
Discussions around United's tactics have centred on how the manager can get the best performances out of his players - in particular, Paul Pogba, who was left out of the starting XI against Chelsea in the Premier League last weekend but played 81 minutes and impressed against RB Leipzig in the Champions League on Wednesday.
Can the Frenchman play with Bruno Fernandes - who faced Frank Lampard's side but was only a late sub against Leipzig - or can they not combine?
The stats suggest both players perform better when the other is not on the pitch - but ahead of Man Utd's Super Sunday clash with Arsenal, Redknapp says, regardless of the system Solskjaer uses, the primary factor in whether Man Utd play well or not is the application from the players in the system.
"Good players can play together," the Sky Sports pundit told The Pitch to Post Preview Podcast. "It's not whether they can play together. They can do. But Pogba has to warrant a place alongside Fernandes.
"When they first played together we all thought it was the dream ticket, people were saying that midfield is as good as anyone's. But of late, it hasn't been.
You can play any system you like but if players aren't going to apply themselves, if players aren't going to get up and win one-on-one battles, it's irrelevant what formation Ole Gunnar Solskjaer plays.
"You can play any system you like but if players aren't going to apply themselves, if players aren't going to get up and win one-on-one battles, if they're not going to get into the box or force the issue with passes, and just setting the tempo of the game, it's irrelevant what formation Ole Gunnar Solskjaer plays.
"You can talk about boxes in midfield, diamonds, but if Paul Pogba is not going to do his stuff it's irrelevant.
"I do think the position he played against Leipzig and the position he played when he was at Juve, when he tucked in off that left-hand side, that seemed to suit him best, where you take away a little bit of that defensive responsibility from him. But with his ability he should have the attributes to play every position.
"When I used to play against Paul Scholes and Roy Keane, I didn't think, 'he's an attacking midfielder, he's a defensive midfielder', I used to think 'he's a midfield player'.
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"We've got so bogged down listening to people talk about tactics and systems too much.
"When you see [Liverpool's] Gini Wijnaldum, you don't go, 'he's playing a two sitting deep'. He just gets after the ball. You see Henderson or Fabinho as the defensive one but apart from that it's just players working harder than the other team.
"That for me is something Man Utd have lacked for a long while. Systems don't make the players, players make the systems. They've got to start acknowledging that, Man Utd players and doing a bit more when they haven't got the ball.
"You look at Fred and no disrespect to Fred, but he comes in and works hard and does a good job for the team. You look at some of the players around him - players who have a lot more ability than him - but the reason Solskjaer's gone to him of late is because he works harder than the other ones."
Solskjaer assessed ahead of his 100th Man Utd game
While Redknapp says players must take responsibility for how they perform in a certain formation or midfield, his assessment of Ole Gunnar Solskjaer's work as manager - ahead of his 100th game in charge of Man Utd against Arsenal on Sunday - was that there is still plenty more room for improvement.
"It was obviously an incredible start," said Redknapp. "When he first arrived we felt it was almost the second coming, a new Alex Ferguson! Everyone was so excited by the regime, we all thought that he'd got this group of players together and made everything better after what Jose (Mourinho) had done. But that was pretty short-lived.
There's a lot more questions than answers now. He's done OK, I'd say, nothing more, nothing less.
"There's a lot more questions than answers now. He's done OK, I'd say, nothing more, nothing less.
"The position United are in is nowhere near where they should be. They've thrown a lot of money at the problem but haven't always bought the right players… so I think if you're to analyse where Ole Gunnar Solskjaer and Man Utd are right now, they should never be in the bottom half of the table."
Pitch to Post Podcast: More from Redknapp on Donny van de Beek, Thomas Partey and his Man Utd vs Arsenal verdict
Listen to the Pitch to Post Podcast to hear more from Jamie Redknapp on Man Utd vs Arsenal, including why he believes Van de Beek is not getting Premier League game time so far this season, how Thomas Partey can transform Arsenal when he gets up to speed, and his assessment of how the big match at Old Trafford will play out.
Also on this week's Pitch to Post Preview Podcast, Sky Sports News reporter Vinny O'Connor has the latest on Liverpool's injury problems and gives us the lowdown on young centre-back Rhys Williams.
And Sky Sports statistician Matt Cheetham picks out the numbers which explain why Everton's defeat at Southampton could just be a blip, and makes his bold Pitch for what will happen in the Premier League this weekend.