Ole Gunnar Solskjaer's dilemmas ahead of Man United's clash with RB Leipzig in the Champions League

The equation would appear to be simple enough - if Manchester United avoid defeat against RB Leipzig on Tuesday night they will be playing Champions League football after Christmas.

But, Manchester United being Manchester United, it isn't as straightforward as all that.

Ole Gunnar Solskjaer faces quite a few dilemmas as he sends his team out in the Red Bull Arena knowing that defeat would mean the unthinkable scenario of dropping into the Europa League.

Not only are there headaches over selection but also in the way United should approach the contest. Nobody is kidding themselves that Tuesday night will see a re-run of the 5-0 battering United inflicted on Julian Nagelsmann's side at Old Trafford in October.

At that point, it looked as though United would reach the last-16 comfortably but it hasn't worked out that way. Now a nerve-racking evening with everything at stake awaits them.

Here are five of the issues facing Solskjaer as United search for the point needed to get them home.

WHAT TO DO ABOUT POGBA?

How kind of Mino Raiola to drop that bombshell about Paul Pogba's future on the eve of United's most important game of the season so far.

Just as Pogba should be fully focused on the task at hand, his agent tosses a hand grenade into the preparations by saying 'it's over for Paul at United'.

Of course, speculation over the midfielder's future is nothing new but the timing was cruel and calculated with Raiola showing a complete lack of class to Solskjaer and United.

Now a big call needs to be made about Pogba's state of mind. Will the Frenchman be fully focused on the game or be distracted by all the furore?

Having scored an eye-catching goal to spark United's comeback win at West Ham on Saturday, Pogba was likely to start against Leipzig, probably alongside Scott McTominay and Nemanja Matic given Fred is suspended after his red card against Paris Saint-Germain last week.

What's more, it's the midfield role Pogba most likes to play, the one where he is trusted to pull the strings and create chances with the backstop of two defensive-minded players behind him.

Donny van de Beek may have been hooked at half-time at the London Stadium, replaced by the far more impressive Bruno Fernandes, but that doesn't mean the Dutchman can't step in for Pogba if Solskjaer feels he isn't in the right frame of mind to start.

HOW TO CONFIGURE THE ATTACK

Injuries to forwards Edinson Cavani and Anthony Martial have made the selection up front simpler for Solskjaer.

Marcus Rashford, who destroyed Leipzig with a hat-trick at Old Trafford, will start up front alongside Mason Greenwood, with both boosted by goals against West Ham at the weekend.

Bruno Fernandes will sit behind them in his No 10 role and be the chief creator as usual. Fernandes didn't start at West Ham after Solskjaer admitted he had suffered a knock but he still had a transformative impact from the bench.

There's absolutely no way he'll start a second game in a row among the substitutes with so much riding on the game in United's season.

The formation is likely to be similar to the one United deployed in the 5-0 win over Leipzig at Old Trafford - a back four, three in midfield behind Fernandes and two forwards.

It goes without saying that Rashford and Greenwood possess not only the pace but the finishing prowess to cause Leipzig considerable damage once again but the service into them will be everything.

DE GEA OR HENDERSON IN GOAL?

The debate over whether David de Gea or Dean Henderson should be United's first-choice goalkeeper has intensified as the Spaniard has struggled with injury in recent weeks.

Forced off at half-time in the win over Southampton after a collision with the post, De Gea was replaced by Henderson but then returned for last week's 3-1 defeat by PSG.

However, Henderson took the gloves again for the West Ham game with Solskjaer explaining that De Gea's knock had flared up again and he'd been left out the squad as a precaution to get him back for Tuesday night.

Henderson ended up playing a key role in United's equaliser, booting what appeared to be a clearance down the touchline (and possibly out of play) straight into the path of Fernandes, who cut back for Pogba to score.

It's led to some suggesting Henderson is better with his feet than De Gea and so should take the No 1 spot.

But De Gea, as the established first-choice, will surely return for the Leipzig game if fully fit.

HOW TO AVOID BEING AMBUSHED BY LEIPZIG

Nagelsmann was left looking rather foolish in his designer suit jacket as his team were crushed at Old Trafford but rest assured he will have a tactical masterplan to get the win Leipzig need.

Some clues can be found in the way they gained a 3-3 draw at Bundesliga table-toppers Bayern Munich on Saturday.

They didn't allow Bayern's players any time on the ball, pressing hard and hunting them down to steal the ball back as quickly as possible, then break forward with speed.

Nagelsmann is likely to go with a four-man defence instead of the three centre backs and two wing-backs he has used in European games in the past and that is probably wise with key defender Dayot Upamecano out suspended.

Fernandes will have to think quick as United's danger man because he won't be given a moment's peace when on the ball, while Matic and McTominay will need to be composed and think two steps ahead.

Solskjaer threw a curveball with his midfield diamond against Leipzig at Old Trafford but even if we were to see that again, Nagelsmann wouldn't be fooled twice. He insists 'lessons have been learned' from that humiliation.

HOW TO APPROACH THE GAME

Solskjaer was certainly bullish in his press conference previewing the game on Monday, saying it wasn't in United's DNA to sit back and play for the draw.

'Anything can happen in any moment. You can't sit back and hope for a 0-0 draw. That's not in our genes, it's not in the team's genes, it's not in the club's genes,' he said.

'We want to go out there and win the game.'

But you almost know for sure that United won't make life easy for themselves. They keep falling behind in games, as at Southampton and West Ham, and can be mind-bogglingly poor in the first half.

It would be refreshing to see United start a game on the front foot and try to grab a goal in the opening 20 minutes. If they can manage that, it will be easier to drop back and try to absorb the pressure.

Solskjaer is right, though. There are so many vulnerabilities in his United team, especially at the back, that sitting back and trying to scrape a goalless draw would be disastrous.

That's not to say they can't invite a bit of Leipzig pressure and try and hit them on the counter-attack, which remains their great strength.

But the German side are a significant step up on Southampton and West Ham. Falling behind to them could easily be fatal to their hopes of extending their stay in the Champions League.