"A coach is like a melon, its exterior might look delicious, whereas the taste is really not," Constantin said in an interview with Swiss newspaper 'Le Matin'.

"When you first meet a candidate he might come across as a competent coach, but when he takes over, he may turn out to be the other way around."

Constantin's bizarre comments come in the wake of his recent firing to coach Uli Stielike, who became the 17th manager to leave Sion in less than five years.

The Swiss side, where Egypt goalie Essam Al-Hadari plays, have been suffering recurring defeats under Stielike, leaking so many goals in the process.

Consequently, chairman Constantin decided to appoint himself as new head coach until the winter break.

Constantin declared that he will give himself a chance or two before deciding to step down as coach.

"I believe I have potentials as a coach, and I will try to convince 'Constantin the chairman' with my technical abilities," he added.

"I am not going to sack myself after one defeat, but if I couldn't stabilize the team I would be fired, just like all those who preceded me. And this wouldn't be a problem because I have no contract as manager."

The 51-year-old is often criticized for being impatient, but he stressed that none of the coaches he installed lived up to the expectations.

"I do not enjoy firing coaches, I feel bad when I do it, but I have never sacked a coach who led the team to first place," he said.