On accompanying Kaká and a Milan delegation to collect the Ballon d’Or in December 2007, Leonardo promised reporters that he would be back next time with Alexandre Pato, the teenage striker he had helped the club sign from Internacional for £19.4m.   Four years later he might still get that pleasure if reports are to be believed that the modish director now in charge of recruitment at the big-spending Qatari-backed Paris Saint-Germain would like to lure his former protégé away from San Siro to the Parc des Princes.   Pato’s future at Milan has come under scrutiny ever since he gave a pair of prickly interviews to Corriere della Sera and Corriere dello Sport on December 27 in which he expressed his disillusionment at…