Celtic: Club could face choice of Martin O’Neill or Robbie Keane

However, although Ferencvaros could not dominate the home field, it showed a superior performance in the Europa League after losing to Karabakh in the Champions League play-off round.

Despite having one of the smallest budgets, Keane guided his team to 12th place in the league stage, four points and nine places above Celtic. Their only defeat was against semi-finalists Nottingham Forest.

The yellow-reds defeated Rangers, Genk, RB Salzburg and Ludogorets on their way to the last 16, and also drew with Fenerbahce.

In the play-off round, they defeated Ludogorets again over two legs and despite a 2-0 home win, they lost 4-2 on aggregate to Portuguese team Braga.

Ferencvaros often played 3-5-2 and Keane often described his football as attacking, once threatening to bring down his centre-backs if they passed to each other too often rather than playing forward.

“I don’t like my centre-backs holding the ball for the sake of holding the ball,” said the former Tottenham, Liverpool and Leeds striker.

Former Celtic captain Scott Brown and youth coach Jonny Hayes have been floated as potential assistants to Keane and former Aberdeen manager Stephen Glass, who was with him in Hungary.

Could he be the man to replace O’Neill? Or could he work with his former international manager at Celtic?