Chelsea's new Egyptian midfielder once refused to shake hands with Israeli footballers after apparently being pressured by extreme groups in his home country.
Mohamad Salah, signed this week from FC Basle for £11 million, sparked controversy when his Swiss side played Maccabi Tel Aviv in Champions League qualifying matches last year.
As the teams lined up for the customary handshake before the first leg of their contest, Salah instead went to the side of the pitch to change his boots.
He was not expected to travel to Israel for the return game a week later on August 6. But the 21-year-old was named in the starting line-up and made minimal contact in the pre-match ceremony - simply bumping fists with the Tel Aviv players.
Salah scored in the game after allegedly saying he would do everything possible to "stop the Zionist flag" appearing in the Champions League, Europe's premier club competition.
He has repeatedly denied that making the anti-Israel statements attributed to him at the time of the game.
Chelsea owner Roman Abramovich and director Eugene Tenenbaum are both Jewish and supporters of Israeli causes.
The Premier League club has not commented on Salah's actions.
The controversy is unlikely to reoccur in the near future - Chelsea are through to the knock-out stages of this season's Champions League, but will not face any Israeli opponents until the 2014/15 season at the earliest.
There are also currently no Israeli footballers in the Premier League.