The defender, who made his first Premier League start since his deadline day switch from Chelsea in Monday's 3-1 win over Coventry, felt pain in the second period of that game and now could miss the clash at Stamford Bridge, however, Roberto described the issue as 'nothing important'.
Speaking on Friday afternoon, Roberto said, "Tosin, we have to see. We have not decided yet. (He’s) a doubt. He felt pain in the second half with Coventry but nothing important."
While Tosin could miss out, Pedro Porro is set to return to the matchday squad after returning to training this week.
James Maddison and Dejan Kulusevski will also both be available but will be carefully managed, with Roberto still unsure whether they can start the game or will be amongst the substitutes.
Lucas Bergvall, Savio, Mykhailo Mudryk, Wilson Odobert, Xavi Simons, Destiny Udogie and Rodrigo Bentancur all remain unavailable.
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