Australia found themselves on the end of a Roy special on Thursday as he hammered 85 to end Australia’s hopes of a seventh World Cup final.
Asked whether he thought the England man could make the grade in red ball cricket he was in no doubt.
He said: “He definitely goes hard having played with him for a few years now for Surrey.
“He’s a player that when he’s on he can be so damaging to an opposition and in such quick time as well.
“I’m not sure what the wickets are going to be like in the Ashes series. So it will be interesting to see how that plays out.
“But he’s got some really good hundreds in county cricket, probably more so in the middle-order.
“That is just one of those things that if he gets going on his day, he can be brutal and he can score so quick in all forms of the game, he is a very dangerous threat no doubt.”
Australia were nursing bruises following the semi-final mauling, no one more so than wicketkeeper-batsman Alex Carey who had eight stitches in a cut in his chin after being hit by a bouncer from Jofra Archer.
He explained: “He’s very tough. I think the grille got pushed back into his (chin) and he had seven or eight stitches in his jaw there and he was a bit sore on the other side.
“But, apparently, he looks all clear for any clinical tests for a fracture or anything like that, so he’s very tough. It would take a bit more than that to get him out of the game.”
Finch was also adamant that yesterday’s defeat will have no bearing on the Ashes squad.
“I don’t think that the guys carry too much baggage when you are going between formats,” he said. “If we rolled up and played a one-dayer tomorrow, there might be a few scars there, but in terms of the Test, I don’t think so.”