Manchester United midfielder Casemiro was trolled by fans for his display in the FA Cup final against Manchester City. The Red Devils lost the Wembley showdown by a score of 2-1.Ilkay Gundogan scored a brace, including a sumptuous volley goal for the opener. While Bruno Fernandes equalized for the Red Devils from the penalty spot, City's second was unanswered.Fans, though, scathed Casemiro for his display. He is one of United's most senior and experienced players. The Brazilian won several major trophies during his time at Real Madrid. However, he couldn't prove to be an influential player against Pep Guardiola's side.He completed only 28 passes and managed no shots on target. Casemiro committed one foul and lost possession of the ball eight times as well. Overall, it was a very lackluster display from the experienced midfielder.Rival fans mocked him for the performance with one writing on Twitter:"Casemiro got schooled by gundogan forget rodri, they DPed him."Another claimed:"Another big game where Casemiro is no where to be seen."Since his arrival last summer from Real Madrid, Casemiro has made 51 appearances for Manchester United so far, scoring seven goals and providing six assists.While he helped the team win the Carabao Cup, Manchester United were defeated in the FA Cup final. Here are some of the Twitter reactions criticizing Casemiro's performance against Manchester City:Bushido Black@Libansofficial@boyrm222 @DxBruyneSZN Casemiro got schooled by gundogan forget rodri, they DPed him3@boyrm222 @DxBruyneSZN Casemiro got schooled by gundogan forget rodri, they DPed himJin Mugen 🇬🇭 🏴󠁧󠁢󠁥󠁮󠁧󠁿@CountDraxulaStones is a better DM than Casemiro.Stones is a better DM than Casemiro.Luther utd 🔰@LutherUtd@totalherrera Casemiro ? Really did you watch the game Only Garnacho or maybe Bruno was decent@totalherrera Casemiro ? Really did you watch the game Only Garnacho or maybe Bruno was decentAlex@Infinite1899Another big game where Casemiro is no where to be seenAnother big game where Casemiro is no where to be seenAdebayo Olumide@DjOlumsFatigue caught up with CasemiroFatigue caught up with Casemirosara@erlsvarezcasemiro highlights against man city517casemiro highlights against man city https://t.co/kYWhht7CpH17@DxBruyneSZNAnother mismatch Casemiro who3881514Another mismatch Casemiro who https://t.co/BXT5qkNdiRDebby🙄@Deb_236Casemiro When there’s no Modric and Kroos holding his hand557195Casemiro When there’s no Modric and Kroos holding his hand https://t.co/xHU4RSFERCManchester United's Casemiro recently spoke about his relationship with Bruno FernandesWhile Manchester United didn't win the FA Cup, there is no denying the fact that Casemiro, alongside Bruno Fernandes, was a crucial player for the team this season.The Brazilian midfielder recently spoke about the relationship he shares with Fernandes. Casemiro holds the Portugal international in high regard. Speaking about Fernandes, he said (via The Peoples Person):"He was always brilliant with me. He taught me lots about the club, what it means. I have a very good relationship with Bruno, we get on really well, and as you get to know him as a player — I can say this with complete confidence — he is one of the most important players at the club. We could spend all day talking about how good Bruno is because he is a fantastic player."Fans will hope that their two midfield superstars continue performing at their very best levels. Whether they can lead Manchester United to more trophies next season remains to be seen.