Manchester United continue to keep tabs on Atletico Madrid striker Sergio Aguero.

Inter Milan boss Jose Mourinho has made Aguero his No 1 target for next summer, reports El Mundo Deportivo, but meeting his £55million release clause would be tricky for the Italians and former Chelsea winger Ricardo Quaresma could be offered in part-exchange.

However, United could yet emerge as a rival for the 21-year-old hot shot.

Sir Alex Ferguson has long tracked the father of Diego Maradona's grandchild but tentative approaches in the summer revealed his huge pay demands.

The champions' spending power has been called into question, but United are tracking Valencia striker David Villa and reports in Spain indicate that Ferguson is excited by the prospect of building a Villa-Aguero-Wayne Rooney attack.