The Three Lions meet Iceland in the Round of 16 at Euro2016 on Monday night but according to captain Rooney, Swansea City star Sigurdsson is not the only one his side should be concerned about.
"I don't want to talk too much about him," the Manchester United captain said.
"He's a fantastic player, he's been very good over the past few years in the Premier League.
"He's a dangerous player, he can score goals from set-pieces and open play. But as I said before we're concentrating on the whole team and not just one player."