Jurgen Klopp, Liverpool, Hoffenheim
Jurgen Klopp expects a professional performance from Liverpool at home against AS RomaReuters

Liverpool legend Phil Thompson has issued a warning to Jurgen Klopp's men and has urged to the Reds to keep a clean sheet when they face AS Roma in the first leg of the Champions League semi-final at Anfield on April 24.

The Premier League outfit sealed a berth after registering a 5-1 aggregate victory over English champions Manchester City. Roma, on the other hand, knocked out Barcelona 4-4 on aggregate, with the away goal rule helping them to progress.

Klopp has the services of Mohamed Salah, Roberto Firmino and Sadio Mane as the star trio to lead his side's attack. The Egyptian international's 31 goals in the Premier League has seen him win the PFA Player of the Year award.

However, Thompson is not worried about Liverpool's attacking division but wants the English outfit to defend. He has also stressed that it is vital for the Merseyside club not to concede in the first leg at home.

"Roma have got the ability to frustrate Liverpool, whereas Manchester City can't do that and Bayern Munich or Real wouldn't do that, so it is a whole different prospect for the team," Thompson told Sky Sports.

"They're direct with Edin Dzeko as the target-man and I'd expect them to target the full-backs with diagonal balls whenever they get into the final third.

"Roma actually played very well in the first-leg against Barcelona and we saw them battle Barca into submission, so we've got to be ready for that.

"We'll have more possession but it is a different sort of game with their defensive strength. Daniele De Rossi is a great defender and a great organizer in front of their backline.

"You want to get off to a good start but, even though we're an attacking outfit, the focus has got be on the defense, to keep the back door shut, as keeping a clean sheet is absolutely crucial because we know what they are capable of back in Rome."