United boss Sir Alex Ferguson used the Norwegian as a 'super sub', bringing him on whenever the team was in need of a goal or a spark, and Giggs has already seen the likeness of the two who following Hernandez's winner against Valencia in the Champions League on Wednesday.
"It's hard not to get too excited by a player like Javier," said Giggs. "We've seen it over the years. You can get excited by players and build them up. But I was genuinely excited in pre-season, seeing what he could do.
"Javier's just a natural finisher and they don't come along that often. You saw that when he scored against Valencia, it was just a great goal. His first touch was great as was his finish. It was just instinctive and when you've got that, you'll score an awful lot of goals.
"He was only on for about 15 minutes but in that time he hit the post, ran through onto a cross when their keeper saved it, and he's just a dangerous player.
"Ole had every finish - left foot, right foot, headers, the lot. And Javier's goal reminded me a little bit of Ole, just because he always used to hit the side netting low and hard, whether it was with his right foot or left foot, and so it was similar in that respect."