Rio Ferdinand has questioned whether Viktor Gyokeres would be a success in the Premier League after watching him blank against Arsenal . The Sporting Lisbon star has been in red-hot form for the Portuguese champions since joining on a free transfer nearly 18 months ago and has been linked with both the Gunners and Manchester United recently. Gyokeres plundered an impressive hat-trick when Sporting triumphed over Manchester City in the Champions League last month. But it was a different story