The Spaniard's inclusion has ignited a troll-fest on social media.

Fans anticipating the FA Cup clash between Chelsea and Manchester United have expressed mixed feelings with regards to Alonso's inclusion in the starting line-up. Some Blues supporters have questioned Sarri's decision to feature the Spaniard in the crucial encounter while a number of United fans find his involvement as laughable.

Marcos Alonso has come under heavy criticisms in recent times with the player having been identified as one among a handful to be blamed for Chelsea's shortcomings.

Although he undoubtedly stands as Sarri's first-choice for the left-back position, fans of the club believe that he is a liability. Instead, many have advocated for the Italian manager to drop the 28-year-old in favor of Emerson. 

Aside the agitation surrounding the inclusion of Alonso, Chelsea named a strong side in its quest to defeat Manchester United in the FA Cup for a record fifth successive season.

Manchester United, on the other hand, will miss the involvement of both Jesse Lingard and Anthony Martial. In the absence of the injured pair, the Red Devils included Romelu Lukaku and Juan Mata in the starting lineup.