I was almost 26 when I had my first taste of the Champions League and, though I'd already played in plenty of big matches for Manchester United and England, it was definitely different.

My second away game was against Galatasaray. About 300 of their fans started to rock our team coach back and forth when we got on at Istanbul Airport.

When we arrived at the stadium to look at the pitch a couple of hours before kick-off, it was already rammed full and bouncing. It was intimidating and you had to be mentally tough. Personally, I found it exciting.

Romelu Lukaku has got off to a fine start with Manchester United after joining from Everton

Romelu Lukaku will not face quite that kind of atmosphere when he makes his own Champions League debut on Tuesday night but, no doubt about it, he is a relatively late arrival at the age of 24 and this competition will help define his career.

It is highly unusual these days for a £75million striker not to have had previous experience and, if he wants to be considered world-class, this is the stage where he has to prove himself.

United's group opponents Basel, Benfica and CSKA Moscow will not be the acid test and he will not be fazed by them, but he needs to learn quickly so he is ready when the real elite stuff comes later in the season; knockout games against the likes of Barcelona, Real Madrid, Bayern Munich and Paris Saint-Germain.

Lukaku has proven he can cut it at the very top of the Premier League

Lukaku is a goalscoring machine and would cause problems to any defence in the world because of the way he runs at people and keeps his composure in the penalty area.

On the other hand, his retention of the ball is not fantastic and, if he goes chasing the ball to get involved in the build-up, United could get punished because top Champions League teams exploit opponents who have lost their shape.

The word I'd urge Lukaku to take on board is 'patience'. His designated area of the pitch should be between the goalposts, never more than 25 yards from the goal-line, maximum. I've seen him move away from that area when things are not going well, when he should be leaving that to Henrikh Mkhitaryan, Juan Mata and the midfielders.

Paul Ince had plenty of experience playing at the top level of the domestic game

I imagine some European games can be frustrating for a centre-forward if they don't feel involved. But they still have to stay in position and be ready when the ball comes.

Lukaku is an asset when he is spinning, running and getting his shots off. He can do that from 25 yards, he does not need to be closer to the halfway line. Studying Zlatan Ibrahimovic will help. When he was asked to be the team's No 9, all Zlatan's good work was around the box. He had great touch and awareness and, if the ball was not close, he conserved energy rather than waste it by chasing. Lukaku's golden rule should be to stay within the goalposts.

Premier League teams are not as feared around Europe as much as they once were. But with five clubs in the group stages this season, it is a tremendous chance for our league.

Zlatan Ibrahimovic will be someone who Lukaku can continue to learn from

I have seen Barcelona this season and they do not seem the same team without Neymar. I detect signs of frustration from Lionel Messi. PSG have great individuals but they cannot be battle-hardened by the French League compared to our teams.

People will accuse me of bias but I genuinely feel my former club United represent the Premier League's best chance of getting to the quarter-finals and beyond.

Jose Mourinho knows how to win and will be going for the throat.

United have great power in their line-up but it is not just power. Nemanja Matic and Paul Pogba might be 6ft 4ins but they can also play. Away from the spine, Marcus Rashford, Mkhitaryan, Jesse Lingard and Anthony Martial have the kind of flair that makes United well balanced.

Jose Mourinho is a manager who knows how to win and he will get the best out of Lukaku

Another former club, Liverpool, are also back in the elite and Anfield will be buzzing on Wednesday against Sevilla. When I joined the club, Robbie Fowler and Steve McManaman told me about European nights, but it was only when I got out there, the song came on and the scarves came out that I realised, 'Wow'.

Philippe Coutinho has to try to copy Luis Suarez the season after he was told he could not leave. One thing about Liverpool fans, as long as Coutinho does things the right way, the fans will still love him.

They will understand the lure of Barcelona and will not hold it against him, just as long as he does not spend his time moping or show the kind of body language Arsenal fans have occasionally seen from Alexis Sanchez. Coutinho does not strike me as that type of player.

There were a few eyebrows raised at Barca's £120m valuation and he will have to shine in the Champions League to show he is truly worth that kind of money.