With Nicolas Jackson away on international duty with Senegal, the belief has been that Broja will be handed a run of starts down the centre of the attack in his absence.
However, head coach Mauricio Pochettino has instead opted to name a front three of Noni Madueke, Raheem Sterling and Cole Palmer, with the assumption being that Palmer will play as a false nine.
Pochettino has made just three changes from the team that started the 4-0 victory over Preston North End in the FA Cup on Saturday, with Alfie Gilchrist and Mykhaylo Mudryk also dropping out of the side.
Thiago Silva, Conor Gallagher and Madueke are the players to be recalled, with Chelsea's injury issues leading to a relatively inexperienced bench being selected.
Meanwhile, Michael Carrick has made four alterations to the Middlesbrough lineup from the 1-0 defeat to Aston Villa, played at the same time as Chelsea's triumph over Preston.
Matt Clarke, Morgan Rogers, Sam Greenwood and Josh Coburn are the quartet that do not feature in the team, with Rogers and Greenwood, who is cup-tied, missing out entirely.
Dael Fry, Jonny Howson, Matt Crooks and Emmanuel Latte Lath have all been handed opportunities back in the first XI, with the formation remaining unclear with three central midfielders and Crooks - who usually also plays in the middle - being named.
Middlesbrough: Glover; Van den Berg, Fry, Engel, Bangura; Barlaser, Hackney, Howson; I. Jones, Latte Lath, Crooks
Subs: J. Jones, Clarke, Gilbert, Coburn, O'Brien, Kavanagh, McCabe, Bridge, Bilongo
Chelsea: Petrovic; Gusto, Disasi, Silva, Colwill; Caicedo, Gallagher, Fernandez; Madueke, Sterling, Palmer
Subs: Bettinelli, Bergstrom, Gilchrist, Williams, Golding, Mudryk, Washington, Broja