In Switzerland, the sale of Basel winger Mohamed Salah to Chelsea means that they will at least be spared one controversy looming next month: the question of whether the player would shake the hands of the Maccabi Tel Aviv players before their forthcoming Europa League tie.

Salah, 21, has been an outstanding, if occasionally frustrating, talent since the Egyptian was brought to Basel from the Cairo club El Mokawloon after the suspension of football in his home country following the Port Said stadium disaster. He brought himself to the attention of Chelsea with his goals home and away against them in Basel’s two shock wins against Jose Mourinho’s side in Champions League group E.

The bigger picture, however, is the allegation that he avoided shaking hands with the Maccabi Tel Aviv players in Basel’s two-legged Champions League qualifier against the club in the summer.

Following widespread suggestions he would not shake hands with the Maccabi team before the first leg in Switzerland in July he moved to the side of the pitch and changed his boots while the pre-match handshakes took place. Under even greater scrutiny a week later in Tel Aviv, he offered a fist-pump rather than a handshake to the line-up of Maccabi players.

Chelsea are owned by Roman Abramovich, one of the highest-profile Jewish people in British public life, who is a staunch supporter of the state of Israel. So too is director Eugene Tenenbaum, a key aide of Abramovich. The club sought assurances that Salah had not made anti-Israel remarks attributed to him, which he has consistently denied having said.

As a replacement for the departing Juan Mata in the Chelsea squad, albeit a very different player, Salah represents an exciting prospect. What the club do not require is any further controversy.

The Salah handshake saga became a major issue in Swiss football in the build-up to the first leg against Maccabi Tel Aviv in Basel. He had been placed under pressure by public opinion in his home country not to shake hands with the Israeli club’s players.

In the event, Salah preoccupied himself with changing his boots at the side of the pitch while the two teams went through their Uefa-prescribed pre-match handshakes. Given that few players disobey or skip the strict Uefa protocols, it was regarded in many quarters as a direct snub to the Israeli team. His club maintained afterwards that it had been a “coincidence” and that no snub had been intended.

With pressure growing around his response in the return leg a week later, Salah was obliged to clarify that he would play in Israel following suggestions that he would not travel there. In Tel Aviv he gave a press conference to distance himself from anti-Israeli remarks attributed to him.

The footage of the handshakes before the second leg game shows Salah at the end of the line of Basel players. Having shaken hands with the referee and his assistants he offered a fist-pump rather than an open hand to the Maccabi players, most of whom reciprocated with an open hand. He was booed by the home fans for the rest of the match.

Having eliminated Maccabi 4-3 on aggregate, with Salah scoring in the 3-3 draw in Tel Aviv, the Swiss side progressed into the Champions League. Finishing third in their group behind Chelsea and the German club Schalke in December, they were placed in the Europa League round of 32 where they drew Maccabi Tel Aviv again.

Salah’s progress has been rapid since he was scouted in Egypt where he made his professional debut as a 17-year-old. He is part of a prolific talent development system at Basel under the club’s sporting director, Georg Heitz, and president, Bernhard Heusler, which has launched the careers of the likes of Xherdan Shaqiri, now at Bayern Munich, and that of the Croat Ivan Rakitic. Heitz and Heusler were key to the negotiations over Salah.

Salah won a Swiss Super League title last year in his first season at the club, albeit with his form inconsistent in that first season. This year he has proved more effective for his club and is a key player in the Egypt national team, which failed to qualify for the summer’s World Cup finals. In the Premier League, he will find himself under even more scrutiny than before.