Unlike Internazionale and Juventus, European champions AC Milan are yet to make their first summer signing as they bid to mount a sustained challenge for the Serie A title. The Rossoneri are keen to acquire a striker following their failure to sign Cagliari's David Suazo, who joined arch rivals Inter, and the departure of Brazilian hitman Ricardo Oliveira on a one-year loan deal to Spanish club Real Zaragoza. And they are setting their sights on the cream of the world's talent. "One of these five non-European players that we are following will arrive," said Milan's vice-president Adriano Galliani. "Those players are Ronaldinho, Shevchenko, Drogba, (Samuel) Eto'o and (Alexandre) Pato." Milan are aware that the chances of signing Ronaldinho or Eto'o this summer are slim, Barcelona having warned the Italian giants that both are unavailable for transfer. The Rossoneri also face tough opposition from Chelsea and Inter to sign 17-year-old Brazilian starlet Pato, who has a contract with Internacional until 2009. And it is no secret that Milan are eager to bring Shevchenko back to the San Siro. The Ukraine international has failed to make an impact since joining Chelsea last summer and is reportedly keen on a return to Serie A.