The former Northern Ireland World Cup striker rates Valencia as being a huge influence on United's fortunes.
"He still hasn't fully integrated into to the side but I'm excited and encouraged by what I've seen so far. He is a fantastic crosser of the ball and now he is starting to get among the goals, I'm predicting big things from him," Whiteside, the 80's hardman still revered at United where he now works on the hospitality and Legends Tour side, told the Belfast Telegraph.
A keen student of the current day United, he observes: "Valencia isn't another Ronaldo. There isn't one. But I did note a statistic that showed Wigan scored more goals from Valencia's crosses last season than United managed from Ronaldo's.
"Ronaldo is irreplaceable nevertheless. What United need to do is replace his goals.
"The two Spanish players (David Silva and David Villa) supposedly coming in might part provide the answer but another solution may already be in place the more Valancia adapts with the increasing quality of his crosses for Wayne Rooney and Dimitar Berbatov."