Lionel Messi's arrival at Paris Saint-Germain has left the club with the most frightening front line in the sport, but now coach Mauricio Pochettino is under pressure to deliver the glory on the pitch that their Qatari owners covet more than anything.

That means winning the Champions League, a competition in which PSG have reached the final and then the semi-finals in the last two seasons.

It also, of course, means reclaiming the French title after Lille beat them to it last season - how could a team containing Messi, Neymar and Kylian Mbappe not win Ligue 1?

"We don't hide that it's our objective," PSG president Nasser al-Khelaifi said at Messi's unveiling when asked about the Champions League.

However, he later told sports daily L'Equipe "it is not an obligation", despite the arrival of the six-time Ballon d'Or winner on a reported salary of €35 million (S$55.8 million) a year.

"We have a great team, but we have not won anything yet," he added.

PSG quickly emerged as the only obvious destination for Messi after the collapse of his new deal with Barcelona, and the player himself admitted the presence of Pochettino on the bench helped sway him.

"Once the negotiations started I spoke with him. I have known him for a long time," he said of Pochettino, who like Messi is Argentinian and started his career at Newell's Old Boys in the city of Rosario.

"The fact he is from Argentina means there is a closeness. I chose to come to Paris because of the technical staff and the squad that's here."

Messi and Neymar, old pals from Barcelona, are delighted to team up again but there is speculation that Mbappe - with just a year left on his contract - is not happy about having to share even more of the limelight.

PSG do not want to let him go though, and Pochettino will have to ensure that fielding that all-star front three, as well as Angel di Maria, does not overly imbalance the team.

That is why PSG's other summer signings are crucial.

The arrival of Georginio Wijnaldum from Liverpool adds much-needed quality in midfield alongside Marco Verratti, while Achraf Hakimi was just what they required at right-back.

Sergio Ramos and Gianluigi Donnarumma are luxury options in defence and in goal.

PSG won their opening game of the league season 2-1 at Troyes last weekend and now host Strasbourg on Saturday, when Messi is set to be paraded before the crowd.

The Argentinian, who has not had a pre-season to speak of, will have to wait a while yet for his debut.

It also remains to be seen if Neymar will feature this weekend following his late return to pre-season training after playing for Brazil in the Copa America.

Ramos is not expected to make his PSG debut at least until next week, but Mbappe will play against Strasbourg amid ongoing talk of a move to Real Madrid.

Lukaku joins Chelsea from Inter Milan on five-year deal

LONDON (REUTERS) - Chelsea signed striker Romelu Lukaku for a second time on Thursday (Aug 12) as the Belgian returned to the Premier League club from Inter Milan, seven years on from his departure.

A Chelsea statement did not mention the agreed transfer fee, but media reports say the deal is worth a club record 97.5 million pounds (S$180 million).