Spurs started their Champions League campaign with a 2-1 home defeat against Monaco. Here are five talking points.

1. A new home, with a hint of familiarity.

It was undoubtedly special for Tottenham to make their return to the Champions League at Wembley.

Spurs banners adorned the walk up to the stadium and the attendance of 85,011 was a club record. The stadium was packed full of white shirts and, as the famous music rang around the national stadium, there was a real sense of occasion.

At the same time there was a little feeling of familiarity. Much of the pre-match build-up was the same as it is at White Hart Lane, and well-known sights and sounds appeared on the big screens and roared out of the speakers.

At kick-off, the atmosphere was electric and the bellows of the mammoth crowd urged Spurs on whenever they approached their opponents’ goal.

This could yet become a formidable home for Tottenham but they have now lost their last five competitive outings at the new Wembley so there is work to be done yet. Fortunately they will not have to wait long to get another go.

2. Team selection.

Mousa Dembele, available for the first time this season after completing his suspension, was named among the substitutes but Mauricio Pochettino appeared to have learned useful lessons from Saturday’s 4-0 victory at Stoke.

Firstly he rewarded Heung-Min Son’s performance with another start, after the South Korean registered two goals and an assist in the Potteries.

Secondly, he benched Victor Wanyama, dropping Dele Alli back into a deeper-lying midfield role alongside Eric Dier and giving the pair a chance to pick up where they had left off at Stoke.

Spurs’ attacking prowess had improved after Wanyama’s withdrawal at the bet365 Stadium - they struck three times in his absence, with Alli among the scorers.

A partnership of Dier and Wanyama can look a little too reserved and defensive and, with Dembele absent from the starting XI again, Alli’s selection in that role was the next best thing.

The aim has to be to win the home games, as Spurs did throughout the group stage in their last Champions League campaign, and some attacking intent is required - although Alli looked too far forward at times, leaving him the wrong side of the ball when Monaco countered.

Dembele and Wanyama were joined on a strong-looking bench by Moussa Sissoko and Vincent Janssen, plus Michel Vorm, Kieran Trippier and 18-year-old centre-back, who continues to be named as a substitute instead of Austria international Kevin Wimmer – a cause of consternation for many fans.

3. A step up.

After all the hype and excitement, Spurs had a rude awakening in the Champions League.

They started brightly but missed chances, notably when Son’s effort was cleared off the line, and were then clinically punished for defensive lapses at the other end as the Ligue 1 leaders struck against the run of play to go 2-0 up after 31 minutes.

The Lilywhites need to appreciate that they truly have taken a step up, that they need to make the most of their chances at this level and that any errors will be costly.

Teams in the Champions League are well-drilled when it comes to shutting up shop and defending precious leads.

Spurs fought their way back into the game, halving the deficit before half-time, but Harry Kane missed a good chance to level as the game entered the closing stages.

Every moment matters more in Europe’s elite club competition. This is the challenge Tottenham’s players have wanted for the last few years, and now they must prove they are up to it

4. Toby Alderweireld is a man for the big occasions.

As the first half drew to a close, Spurs were 2-0 down and the crowd was subdued. Alderweireld’s header from Erik Lamela’s corner changed all that.

The Belgian’s four goals last season came against Manchester City, London rivals West Ham, Arsenal and Manchester United, proving he is a big-match player – and this was a timely moment for him to strike again and open his account for this campaign.

It lifted his team-mates and, just as importantly, the crowd. Moments later Alli was inches away from connecting with Lamela’s cross in front of goal, and Spurs’ players left the pitch for the half-time break with cheers ringing in their ears.

5. Impact substitutes.

Pochettino acted proactively at half-time and swapped Son for Dembele, moving Alli forward into the No10 role.

Perhaps it was because Alli had been playing a relatively advanced role for much of the first half anyway, and Pochettino wanted to retain his goal threat while adding some stability in front of the back four – or perhaps it was to make use of Dembele’s dribbling ability against a Monaco side that planned to sit inside their own half and play on the break.

Either way, the Belgian helped Tottenham to get on the front foot right from the start of the second period and put the visitors under sustained pressure, winning a succession of corners.

Janssen also appeared as the half wore on, followed by Sissoko, with the pair playing up front and on the right flank respectively.

Both players created chances – Janssen teeing up Kane and Sissoko driving forward and intelligently picking out Alli, who shot wide from the edge of the box – but Tottenham were unable to find an equaliser.

Follow me on Twitter @BenPearceSpurs