The 2021-22 footballing season is off to an exciting start, with action heating up in Europe’s top five leagues.The season-opening transfer window was undoubtedly the most entertaining one in recent memory. The likes of Cristiano Ronaldo, Lionel Messi, Romelu Lukaku, Raphael Varane and several others have completed moves to new clubs over the summer.Ronaldo established his dominance once again at Manchester United, most recently scoring a brace in the Red Devils’ 2-2 draw against Atalanta. However, the likes of Messi and Jadon Sancho have struggled at their new clubs.On that note, let’s take a look at the five world-class attackers who are currently out of form.#5 Jadon SanchoJadon Sancho has failed to hit the ground running at Old TraffordManchester United’s long search for a right winger finally materialized with the £76.50-million signing of Jadon Sancho from Borussia Dortmund.The young Englishman established himself as one of the finest operators in his position during his four-year stint at Signal Iduna Park. He also had prior experience in English football with Manchester City’s youth set-up, and there were huge expectations upon his arrival at Old Trafford.ESPN UK@ESPNUKJadon Sancho could become the next Donny van de Beek if he's not careful, according to Gary Neville 👀11:36 AM · Nov 2, 20211707124Jadon Sancho could become the next Donny van de Beek if he's not careful, according to Gary Neville 👀 https://t.co/FQF5VLxG1vThe 21-year-old has failed to hit the ground running at his new club. He has been unable to notch up a goal contribution in 12 appearances across all competitions and has mainly featured from the bench in recent games. Six of Sancho’s appearances this season have been as a substitute.Ole Gunnar Solskjaer has recently made tactical changes to fix Manchester United’s leaky defense, employing five defenders at the back. This takes the right winger out of the game, and we could see even less of the talented youngster in the coming months.#4 Eden HazardEden Hazard has failed to live up to his potential at Santiago BernabeuEden Hazard left Stamford Bridge as one of the best forwards in the modern game, but he has been a shadow of his former self at Real Madrid.Injuries haven’t helped the Belgian either, as he has been restricted to the sidelines for a major chunk of his Real Madrid career. However, the 30-year old has remained relatively injury-free this season, making 10 appearances for Los Blancos across all competitions.Despite notching up an assist in his first game of the season, Hazard has failed to make any real impact since.Frank Khalid@FrankKhalidUKEden Hazard could be on his way out of Real Madrid next summer with both Chelsea and Newcastle reportedly willing to give him a chance.The Belgian's had a tough time at Real, scoring just five goals in 53 games since joining the club in 2019.6:28 AM · Nov 2, 2021115479Eden Hazard could be on his way out of Real Madrid next summer with both Chelsea and Newcastle reportedly willing to give him a chance.The Belgian's had a tough time at Real, scoring just five goals in 53 games since joining the club in 2019. https://t.co/u7600N6XHWThe Belgium captain was left on the bench in some of Real Madrid’s most important games this season, including their most recent El Clasico fixture. Five of his nine La Liga appearances have come from the bench.Hazard has now fallen down the pecking order behind Karim Benzema, Vinicius Jr., Rodrygo and Marco Asensio.Real Madrid manager Carlo Ancelotti has even revealed that he prefers other players ahead of the former Chelsea star. Here's what he said recently:"He can play 4-3-3 on the left or 4-4-2 above or behind the striker. He is ready to play, but the problem is that there is a coach who prefers another player. He does not have a star status at Madrid because he has had many injuries and little by little he will have his best version."He added:"I am sure that this season we will see his best version and that he will play more than he is doing now. Hazard has it. Everything: quality, motivation. He has to endure, what happens is that sometimes the coach prefers other players."