A shame it didn't work out for him, but injuries have played a huge part in that. I feel that we never got a fair chance to judge him and so I definitely wouldn't put him under the "flop" category for that reason.
This does mean that three of the attacking reinforcements we had lined up (Arriola, Morris and the Southampton kid) have had injuries ruling them out for significant periods and Hourihane will make it four (how long he could be out with nerve damage is anyone's guess). I don't know how far away Cullen is from returning but assuming he isn't available for a good while that leaves our attacking force without 5 of the 8 players we had lined up to cover those positions.
Lowe is in a serious slump right now, Ayew needed a rest and did not get it and Whittaker is green and needs time to get experience.