Man City defence not good enough to win Champions League - Chris Waddle

Sergio Aguero has scored two or more goals in a game seven times this season

Manchester City beat Monaco 5-3 with a fantastic performance in the best game I have seen this season, but the way they did it also showed why Pep Guardiola's side will not win the Champions League this season.

I could say the same about Monaco - like City they looked very dangerous when they attacked, and both sets of fans will talk about Tuesday's match for years, but neither side's defence is good enough to win the competition.

Going forward, City were brilliant. Their mind-set was impressive too - they were behind twice but stuck at it and got their rewards.

City will be confident of scoring against any team, but they also gave away some very poor goals and it is a lot harder to win the Champions League that way, by outscoring the opposition.

I just cannot see City keeping a clean sheet and there are too many more disciplined teams left in the competition who will not give them the same number of chances Monaco did. I think they will get found out in the end.

If City try to shut up shop, they will lose

The graphic showing average position of touches by Manchester City and Monaco players illustrates how attack-minded both teams were. Yaya Toure (42) was City's only sitting midfielder in their 4-1-4-1 formation

I am not surprised Guardiola says his side will fly to Monaco for the second leg looking to score as many goals as possible.

I cannot see City playing any other way because, defensively, they are not the best - however they are set up.

They could put another midfield player in front of their defence instead of just having Yaya Toure there as they did in the first leg.

If they have full-backs Aleksandar Kolarov or Gael Clichy available by then, that would allow them to put Fernandinho back in there after he filled in at left-back on Tuesday. Guardiola could pick the more defensive-minded Fernando in the middle too, which would help.

But I think Guardiola knows City's strength is with their attacking and creative players. When they were brave on Tuesday night, they were dangerous, and that is what they have to do in Monaco too.

City created chance after chance when they got past the Monaco midfield and exposed their centre-halves, so I am not surprised that Guardiola wants them to do more of the same next time they meet.

People might wonder why he wants his team to be so open but if he was thinking that they should sit back in Monaco and take the punishment, he is asking for problems.

Basically, City have to stick with an attacking approach because, if they go there and try to shut up shop, they will lose.

Why City's full-backs will keep going forward

City and Monaco both used the flanks when they attacked on Tuesday. City favoured the left, where Leroy Sane frequently combined with Fernandinho, Kevin de Bruyne and David Silva. Monaco preferred the right, where Djibril Sidible constantly broke forward and Bernardo Silva saw a lot of the ball.

We saw again on Wednesday night that City's defence is something they have to work on - but it should not be their focus in Monaco.

Guardiola will want his back-line to be more disciplined than they were at Etihad Stadium but, in the space of three weeks, he cannot mould them into a solid unit that will be able to keep Monaco out.

Why would he want to? City play an expansive style, and that means they always leave a lot of space at the back.

If Guardiola were a defensive-minded coach, then City's full-backs would stay close to their centre-halves and also be back in position to block some crosses.

Monaco were terrific when they attacked down the flanks and put in some brilliant crosses, so he knows that is one way they will threaten on 15 March.

City could concentrate on stopping that from happening by keeping their full-backs deeper and denying Monaco's wide players space to run into.

But Guardiola wants his full-backs to join in with City's attacks too. It means his centre-halves can quickly become isolated when the opposition win the ball back and break, but I understand why he is willing to let that happen.

His teams at Barcelona and Bayern Munich never just sat back and defended. Yes, Guardiola likes possession, but he also likes to play on the front foot.

First goal will be vital in the second leg

"Some people might look at Falcao's goal and think 'nah it is not that good, he just chipped the keeper' but he did it from 12 or 13 yards out, when the keeper was six or seven yards away. It had to be perfect, and it was. That is an unbelievable bit of skill, and he made it look so easy."

Wednesday's game had everything you could want from a football match. In terms of entertainment, it was 10/10 and Radamel Falcao's chipped goal for Monaco was in the all-time top 10 of the best I have seen.

The second leg is extremely hard to call, other than that I think Monaco will attack and I also think they will score. It could end up another classic match.

The pitch at Monaco's Stade Louis II is bobbly and not as good as the surface at the Etihad, so it could be that the tie is decided more by mistakes than by moments of quality.

City are in the driving seat but they have to go out there being positive and look to score first. If they do that, then Monaco's heads could go down.

But if Monaco get the first goal then it could turn into a very difficult night for Guardiola's side. The pressure will really be on.

There will be goals, and there might be moments when the tie is in the balance. Hopefully they will go City's way.

Chris Waddle was speaking to BBC Sport's Chris Bevan.