Schalke general manager Horst Heldt branded the team's 5-0 home defeat to Chelsea in the Champions League "embarrassing" and "unacceptable".
Jose Mourinho hailed Chelsea's "complete" performance after their 5-0 demolition of Schalke.
Chelsea cruised into the knockout phase of the Champions League on Tuesday night with a convincing 5-0 win over Schalke.
Schalke boss Roberto Di Matteo says there is no room for sentiment when he faces old side Chelsea on Tuesday night
Schalke warmed up for the visit of Chelsea in the Champions League on Tuesday by beating Wolfsburg 3-2.
Roberto Di Matteo faces his first real test at home since becoming Schalke coach when the Royal Blues host Wolfsburg.
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