And Rooney has been knocking them in, he has 26 Premier League goals to his name this season, the problem was he has suffered with injuries and there has been nobody at the club who could do the job half as well as he could.
Giggs believes that with another goalscorer at the club, United could have won a few more games and gone on to out gun Chelsea who scored 103 for the campaign.
The losses of Cristiano Ronaldo and Carlos Tevez have not helped.
"If you had to say one thing, you'd probably say we can't rely on Wayne next season like we did this one," Giggs told the Daily Mirror.
"We need to be scoring more goals from different areas and from different players, even though as a team we scored more than we did last season.
"We were also better defensively this season than last, but we can't rely on Wayne as much as we have done this season in terms of goals.
"On Sunday against Stoke we started full of hope, then came in at half-time and found out Chelsea were 2-0 up and Wigan were down to 10 men.
"We knew then it was over and, to be honest, we didn't want to go out for the second half. You just want to go home in that situation."