Barring a banana-skin against Burnley, Liverpool have enjoyed a fantastic start to the season, rocketing to fourth in the Premier League table before this weekend's round of fixtures and claiming impressive results over Arsenal, Chelsea and Tottenham Hotspur in the process.

But a meeting with Manchester United on Monday night represents arguably their toughest test so far this term. The Northwest Derby is always a cagey, feisty and bitter affair and but Jose Mourinho's presence in the Red Devils' dugout adds yet another intriguing subplot to the biggest fixture on the Premier League calendar.

Most still see the Reds as the favourites; after all, they boast home advantage and Mourinho's United revolution has hardly set the world alight so far. But United are still incredibly tough customers and Klopp is faced with a couple of key dilemmas ahead of Monday night's 8pm kickoff.

We take a look at four that could decide the result of the Northwest derby.

HOW CAN LIVERPOOL AVOID A STALEMATE?

The biggest danger of hosting a Mourinho side in a high-profile match is an obvious one; the master of the away draw turning the game into a complete stalemate. Klopp certainly wouldn't turn his nose up at a point taken from their northwest and potential title rivals, but he'll know Liverpool can do better - especially entering Monday night off the back of four straight wins in the Premier League.

Mourinho may well use Chelsea's 2-0 win over the Reds at the end of the 2013/14 season, a game famed for killing off the Reds' title push, as the template to follow, so Klopp must ensure his side don't get bogged down in the same way as Brendan Rodgers' did two years ago.

How can that be avoided? Liverpool need to kick off with a Blitzkrieg, something their mobile, lightning-paced attack is more than capable of doing. City exposed United's inability to withstand heavy pressure in their own half, particularly when on the ball, during the Manchester derby and this Reds team has the right components to produce a similar kind of high-intensity performance.

CAN THE DEFENCE COPE WITH ZLATAN?

If Liverpool are still plagued by one flaw, it's an overall lack of height. Indeed, Klopp's usual front five are all of the slight and mobile build and although holding midfielder Jordan Henderson measures in at 6 foot 2, he's not exactly renowned for dominance in the air.

That could be a real problem upon facing the Red Devils; Mourinho's teams always carry a strong aerial threat and nobody in his United incarnation epitomises that better than 6 foot 5 front-man Zlatan Ibrahimovic, who has already bagged two headers this season.

It's likely United will take a direct approach to try and counteract Liverpool's high pressing, which means lots of long balls for the Swede to win in the air. So how can the Reds contain Zlatan's aerial menace?

It could require bringing Emre Can, a 6 foot 1 utility man with experience playing in the backline, into the engine room to offer added protection just in front of Ibrahimovic, essentially suffocating him with the two centre-backs squeezing from behind. That would solve another issue for Klopp, which brings us onto...

WHO COMES IN FOR WIJNALDUM AND LALLANA?

Adam Lallana and Georginio Wijnaldum's efforts in the engine room have been instrumental to Liverpool's strong start to the campaign, combining energy and mobility with quality on the ball. Lallana alone has bagged three goals already this season, but both could be absent through injury for Monday's game.

As previously mentioned, Emre Can is the natural choice to come into the side. He's been limited to substitute outings so far this season but the German international is the kind of player you'd want in such a high-quality contest, with good physicality and a strong defensive game.

But that will only solve one absence; other options include youngsters Marko Grujic, Kevin Stewart and Cameron Brannagan, enforcer Lucas Leiva or moving ad hoc left-back James Milner back into midfield - meaning Klopp will have to place his faith in Alberto Moreno.

Overall, none of the choices are particularly convincing, so the Liverpool gaffer will hope at least one of Wijnaldum and Lallana win their races for fitness.

HOW CAN LIVERPOOL STOP GOALS FROM CORNERS?

An extention of the aforementioned issues regarding height, no Premier League side has scored more goals from set pieces than Manchester United this season, four, and that could spell serious trouble for the Reds on Monday.

Indeed, Liverpool are infamous for their shoddy defending at set pieces and although the summer arrival of Joel Matip has brought some improvement, old bad habits die hard. It always feels as if the Reds are just one corner away from sloppily conceding.

Facing United in particular, Klopp must come up with a plan. The added height of Emre Can would certainly help but it might also be worth leaving just one player - or perhaps even none - out of the box when defending corners in the hope of finding strength in numbers.

It may seem a simplistic issue, but poor organisation and a failure to attack the ball at set pieces could well be what decides a cagey Northwest Derby at Anfield.