Sunderland have been mentioned alongside a prolific attacker in the English Football League. The summer transfer window is now officially open. But for Sunderland, the ongoing search for a new manager will surely impact upon the club’s summer transfer business. Sunderland are nearly four months without a manager and continue to see linked names fall out of contention. Liam Rosenior is the latest, joining Will Still and others in pursuing other opportunities, if not landing an entirely new job in itself. Sunderland fans are venting their frustration at Kristjaan Speakman amid the ongoing manage…