The Blues, who won the Champions League in 2021 under Thomas Tuchel, travel to the Bernabeu on Wednesday night for the first leg of the quarter-final tie.
Chelsea are certainly outsiders ahead of the last-eight encounter, having slipped into the bottom-half of the Premier League this season under former manager Graham Potter.
Potter was sacked after less than seven months in the job but caretaker manager Frank Lampard has not had an instant impact at Stamford Bridge, with Chelsea slipping to a 1-0 defeat to relegation-battlers Wolves at the weekend.
Real Madrid are not enjoying their best season – falling 13 points behind Barcelona as they bid to defend the La Liga title – but have impressed in Europe, knocking out Liverpool on their way to the quarters.
Carlo Ancelotti’s side won the Champions League last season and Merson says Real Madrid could batter Chelsea unless the Premier League side make major improvements.
‘There was no urgency from Chelsea [against Wolves], it was very slow,’ Merson told Sky Sports.
‘For about 15 minutes in the second half they [Chelsea] moved it quickly and were going through Wolves without making chances.
‘They were getting it out wide and getting crosses in. A bit more luck here and there and you never know.
‘The only benefit of the doubt I can think of is they’re waiting for Wednesday night [vs Real Madrid]. If they turn up like that it will be pointless going to the second leg, it could be a cricket score.’
On a positive note for Chelsea, Thiago Silva, Mason Mount and N’Golo Kante were all spotted in training ahead of their trip to Madrid.
Mount and Kante both missed Saturday’s trip to Wolves while Silva has been out since the end of February with injury.
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