There was nothing smooth about the Mexican's Community Shield goal - United's second - as his mis-hit shot flew in off his face - but Giggs views Hernandez as a major plus in United's quest for honours.
"Javier has the extra quality that makes a difference," he said.
"Towards the end of last season we needed that player who could come off the bench and change a game.
"Now we have strengthened and hopefully that will give us an edge.
"Javier is a goal-poacher. His overall movement and ability to find space is really good.
"Hopefully he can get a lot of goals this year. He has started pre-season really well and I am sure he will be a great player for us."