Arthur Wainwright signed for Leeds City in 1914, but had to wait a year for his first team debut. After action with Tinsley Working Men's Club, City gave him a chance. With the club requiring playing reinforcements after the start of the war, Wainwright was called into the squad while working in a local khaki factory.

Jack Hampson was injured and Wainwright deputised at centre-half at home to Hull City on 2 October 1915 as City won 3-1. Hampson returned the following week, but Wainwright retained his place, switching to right-half so that skipper George Law could fill in at right-back. City lost 2-0, with the Yorkshire Evening Post claiming that he 'has not the speed necessary to keep a fast left wing in check'.

By the end of the month, Wainwright had quit Elland Road to join the Royal Garrison Artillery. His farewell appearance, in a reserve game, was controversial.

The Yorkshire Evening Post reported that Wainwright 'was requested to leave the field by Mr H Brown of Leeds, the referee, for using bad language in connection with one of his offside decisions. Wainwright, however, refused to comply with his request, and Mr Brown blew his whistle for the cessation of play. As the referee approached the touchline leading to the dressing room, Mr Cripps, a local enthusiast who has done so much for local junior football, and is a League linesman, went out of his way to try to get him to alter his decision, but Mr Brown was obdurate. Not to be beaten in his efforts to secure a continuation of the play, Mr Cripps persuaded one of the linesmen to take up the duties of referee for the remainder of the match, his place being taken by another gentleman, while the other original linesman was not to be seen afterwards.

'No doubt the incident will be brought before the proper local governing authority, and adjudicated upon, and without referring in any way to the action of Mr Cripps, one may be persuaded to observe that the referee in no sense exceeded his authority. He was the sole arbiter in the matter and the referee's decision in well-regulated football is always upheld.

'Even when play was recommenced, Wainwright was still in the team, but in a few minutes the City's assistant trainer persuaded him to leave. Possibly Wainwright alone of those players who believe that at present time the laws governing the game will not be so strictly enforced as in normal times - an idea which is as injurious to the game as is fallacious.'

Wainwright returned to City in 1919, but had still not made a League appearance by the time the club was disbanded following illegal payments to players during the war. He was among the men infamously auctioned off in October 1919, joining Grimsby Town for £200.

Wainwright scored twice in eight games for the Mariners before leaving for Gresley Rovers. He returned to league football when signed by Bristol Rovers in 1922, later moving on to Barrow before drifting thereafter into non-league football.