West Ham boss Allardyce hails Downing debut performance
"There's no need to ask Stewart if he can prove himself because he's already done that. He's a top quality Premier League player and has been for a number of years," Allardyce said.
"We didn't start him because he was short of match time during pre-season. Cardiff were tiring and the spaces were getting wider, so off he went.
"What he contributed was exciting and he's glad to be here, that's the most important thing. We hope he gave the crowd a look at something they'll see all season."
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