Joe Allen says Wales missed the influence of key players Gareth Bale and Aaron Ramsey during the international friendlies against Ukraine and Northern Ireland.
Wales lost 1-0 to Ukraine on Monday, after drawing 1-1 with Northern Ireland last Thursday, and Chris Coleman's side are now without a win in their past three games since sealing qualification for Euro 2016.
Real Madrid forward Bale and Arsenal midfielder Ramsey played no part against Ukraine and Northern Ireland, and the pair also sat out the 3-2 home loss to Netherlands in November.
And Allen believes it is no surprise that Wales' struggled in their absence.
"Any international team would miss players of that quality," said Liverpool midfielder Allen.
"To have the chance to welcome them back into the group is a massive bonus for us. It's going to help bring the real best out of the team.
"Whether it is a friendly or not, the result is important, but it's not the be all and end all at this stage.
"Teams in the past have flown through friendlies, drubbed teams and then disappointed. So I don't think it's too much we will look at."
Wales face England in the European Championship group stage, as well as Slovakia and Russia, and Allen said Wales will work on their defensive frailty from set-pieces.
He added: "We will analyse the way we have performed, any strengths and weaknesses, and work on them.
"We have played 180 minutes without conceding a goal from open play, and that shows how defensively strong we can be as well.
"It's something we pride ourselves on in the past and we will keep working and make sure we get it right when the Euros do come around."
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