Chelsea suffered a shock 5-2 loss to West Brom at Stamford Bridge on Saturday’s early kick off clash.
Christian Pulisic opened the scoring for the hosts before Thiago Silva was sent off for two bookable offenses.
Mathieus Pererra scored two late goals in the first half to hand West Brom a 2-1 lead going into the break.
Chelsea capitulated in the Second Half as West Brom scored three more goals to earn a vital victory.
Mason Mount scored a consolation goal for Chelsea to make it 5-2.
Tuchel said Chelsea could not adapt to the situation after going a man down.
“There is no need to concede five goals when you have our quality,” he told BBC Sport. “We are all in on that – myself included.
Chelsea will be back in action on Wednesday in the Champions League against Porto.