Remove the wheel and the QR. Now try gripping the stub ends of the axle and try to see if there is movement. If there is then the cones need adjustment and the net will show you how although you will need the correct size of cone spanners to do this.
If by "wobble" you are referring to the rim's movement as it passes the brake blocks and there is no slack in the cones, then your wheel has gone out of true and will require the spokes re-tensioned and trued before stressing and de-stressing.