Liverpool hero Ronny Rosenthal has questioned his old club's move for Milan Jovanovic.
The Serbia international revealed a pre-contract agreement with Liverpool yesterday. The striker is leaving Standard Liege at the end of the season on a Bosman.
Rosenthal, who has played for Liverpool and Standard, warned: "Defenders in England are five times better than in Belgium.
"Jovanovic will need to improve physically and skills-wise."