Manchester United great Rio Ferdinand has dubbed referee Peter Bankes's decision to dismiss Casemiro against Chelsea as 'harsh'.
With the Red Devils 2-0 up and coasting, the Brazilian midfielder was given his marching orders on the brink of half-time for a challenge on Andrey Santos.
While already on a yellow, Casemiro attempted to win the ball off the Blues winger with a sliding challenge from behind. He got the ball but in the process brought down Santos with a tackle deemed worthy of a second yellow by the referee.
He left the field in disbelief, shaking his head endlessly as he walked towards the tunnel.
The 33-year-old veteran had been booked, a definite yellow card, earlier in the half for a late challenge on Enzo Fernandez in midfield.
Taking to X at half-time, former United centre-half Rio Ferdinand criticised Bankes' dismissal of Casemiro.
Rio Ferdinand described Peter Bankes's decision to dismiss Casemiro as 'harsh'
The Brazilian was given his marching orders on the brink of half-time for a challenge on Andrey Santos
He wrote: 'Positive 1st half…. Enjoying seeing us cross the ball - making Chelsea defend… Both goals from crosses..
'Got a 6ft 5 CF - put the ball into him and let him make it uncomfortable for the defenders - flick on for the red card.
'Casemiro - given the referee the option. Harsh but allowed him to even it up. Need to keep being positive 2nd half.'
It had been a chaotic first-half at Old Trafford beginning in the opening exchanges when Robert Sanchez was dismissed.
After Benjamin Sesko won a flick-on, the Spaniard brought down Bryan Mbuemo as the United winger took the ball around him, leaving the referee with little choice but to hand 'keeper a straight red.
Maresca then made a host of early changes, with Pedro Neto and Estevao taken off for Filip Jorgensen and Tosin Adarabioyo within the ten-minute mark.
The Blues then suffered a huge blow as Cole Palmer was withdrawn early on with what looked like an injury.
United went on to put themselves two goals in the lead before Casemiro's dismissal in a game so crucial for Ruben Amorim.
Bruno Fernandes scored the first with a close-range effort on a soaking wet day in Manchester, before Casemiro headed home the second.