The first wave of Manchester United's players reported back to Carrington on Monday morning for the start of pre-season training. Just over five weeks after their post-season tour of Malaysia and Hong Kong came to an end, United are now preparing for the start of the 2025/26 season. The Reds will play five friendlies ahead of their Premier League opener against Arsenal on August 17. A total of 15 players reported back to Carrington on Monday morning, including new signings Matheus Cunha and Diego Leon, but those who represented their countries on international duty at the end of last season are not expected to return until Thursday. Nevertheless, it should not be too long before head coach Ruben Amorim is reunited with his full squad and preparations for the forthcoming campaign can really begin to take shape. Ahead of United's pre-season opener against Leeds United in Norway a week on Saturday, MEN Sport has picked out six players who will have a point to prove this summer. Andre Onana Onana was linked with a move to French club AS Monaco recently, but has returned to Carrington under the impression he will start the new season as United's No.1. He was guilty of making too many errors last term, sparking calls for him to be ditched as Amorim's first-choice goalkeeper. As reported by the Manchester Evening News back in January, Amorim wants to sign a new shot-stopper this summer, but the likelihood is Onana will retain the starting gloves. If that is to be the case, his performances between the posts must improve. Amorim wants a new keeper to compete with the Cameroonian, meaning that should motivate the former Ajax man to raise his game. With less than 12 months left on his existing deal, it remains to be seen if Casemiro will still be a United player come the end of the transfer window. He has made no secret of his desire to stay, but the absence of European football in 2025/26 could force United's hand. Casemiro's Europa League performances were excellent in the second half of last term, but his domestic performances left a lot to be desired. He struggled with the speed and the intensity of the Premier League. No club has so far submitted an offer for the Brazilian. His pre-season performances may also have a decisive say in United's thinking regarding his future. Manuel Ugarte Signed from Paris Saint-Germain almost a year ago, Ugarte was expected to fix United's midfield woes. Instead, he is not guaranteed a regular starting berth ahead of the new season. As good as he often was defensively, his ability on the ball was frequently questioned. The Premier League is played at a much quicker tempo in comparison to what he had been used to in France and Portugal. At the age of 24, Ugarte still has time to improve and adapt, and a first full pre-season at United could help him. But if he is to occupy one of the two central midfield spots come the start of the season, a solid pre-season feels imperative. Mason Mount It is no secret just how much Amorim admires Mount, meaning there is every chance he could play a very important role in the Portuguese's plans for 2025/26. His United career has been plagued by injuries thus far and he will be determined to make up for lost time. He offered glimpses of his capabilities towards the end of last season and scored twice in the Europa League semi-final second leg triumph over Athletic Club at Old Trafford. The question everyone will be asking will be can he stay fit? If he can stay injury-free there is every chance he will have a big role to play. Joshua Zirkzee After joining United last summer to operate as a No.9, it quickly became clear that Zirkzee had never been a natural goalscorer. Fortunately for him, he was able to flex his muscles as a No.10 in Amorim's 3-4-2-1 system. That role suits him down to the ground, so much so he was just getting into his stride when he encountered a hamstring injury in April. However, United have signed Matheus Cunha and hope to add Bryan Mbeumo, meaning United's No.10 options could soon be stacked, limiting Zirkzee's game time. He is unlikely to have a long-term future at Old Trafford, meaning a sale this summer cannot be dismissed. His pre-season performances may dictate United's thinking. Rasmus Hojlund With the addition of a striker United's top priority this summer, they are prepared to sell Hojlund. He has generated interest from Inter Milan and has also been linked with a move to Napoli. After a solid first season at United saw him score 16 goals, he regressed last term, scoring just 10. Patience is wearing thin and United desperately need a new No.9. However, the Dane has not had a full pre-season at the club since arriving from Atalanta nearly two years ago, meaning this summer could be a make or break period for him.