We probably shouldn't have signed him in the first place — guess the rationale was that he would give us greater control in matches and drive the team forward (suspect the seed of doubt was planted in Fergie's mind after the Champions League loss to Madrid/Redondo in 2000 where they outmaneuvered us in midfield), but Verón thrived when he had the freedom and time to dictate to proceedings in his own inimitable way, and we already had plenty of dominant midfielders in Beckham, Keane, Scholes (who were unlikely to take a backseat to him or afford him the time to play at a more leisurely tempo). Furthermore, at Lazio the likes of Roberto Sensini or Matías Almeyda would cover/sweep for Verón and Stanković — he wasn't offered the same kind of security blanket at United on a consistent basis.
In fairness, he had a good start to his United career but once Fergie started to move back to his tried and trusted methods, the writing was on the wall. This match was the beginning of the end with regard to the short lived packed-midfield experiment, and Verón's form/performances deteriorated quite a bit in the following weeks and months...
A flop because of his price and the expectations associated with signing a borderline Galáctico level player in an era where the best of the best usually joined Italian clubs or the Spanish Big-2 when at the peak of their powers, but there were mitigating circumstances — a fair few of them beyond his individual control. Nedvěd was the Lazio player we should have aimed for, even without the benefit of hindsight — more more suited to the English game because of his headstrong nature, effervescence, agility, stamina and tactical malleability — and wouldn't have disrupted the central midfield dynamics that much.