The demise in Paul Le Guen’s managerial career is becoming more shocking by the day, reaching its worst point yet yesterday when eight police vans arrived to protect the former Rangers manager and his Paris Saint-Germain players at Camp des Loges, the PSG training complex on the outskirts of the capital.

Le Guen’s team sit eighteenth in Ligue 1, mired in the relegation zone, with PSG fans becoming more militant by the day. Le Guen remains a hero to the club’s supporters, having been an iconic player in Paris in the mid1990s, yet that goodwill towards their coach is ebbing by the week as PSG’s form goes from bad to worse.

Le Guen’s team have yet to win a league match this season at the Parc des Princes, having won only three of their 16 league games so far. But what has startled and amazed the club’s supporters – in an echo of Le Guen’s fate at Rangers – has been their manager’s “shock therapy” in his bid to turn the club around.

Le Guen has ruthlessly gutted his PSG team of its foremost players. He dropped Pauleta, the iconic Portuguese striker, and he also axed Marcelo Gallardo, the club’s established Argentina international, whose form under Le Guen has dipped. When Sylvain Armand, the PSG captain, also showed signs of faltering under Le Guen, he too was despatched to the bench or dropped completely.

In Armand’s place, Le Guen chose to take even his daring and temerity to new heights. The former Rangers manager installed Mamadou Sakho, a 17-year-old, as the PSG club captain, and threw two other youngsters, Younousse Sankhare and David N’Gog, both just 18, into his team. Sakho, Sankhare and N’Gog are all young black players from the suburbs of Paris, representing classic examples of PSG’s youth policy in the city, but so far it has all proved too much for them. Le Guen’s shock therapy isn’t working.

When a club’s luck is out, it almost seems to become self-perpetuating. On top of a series of disastrous results for Le Guen – losing 3-1 to Lorient, 3-1 to Rennes and 3-2 to Lyons, all at home, on top of endless and infuriating 0-0 draws in Le Parc – his team went to Caen last weekend. There, just when PSG appeared to be prevailing, Ceara, the Brazilian central defender, tried to dribble out of defence, lost the ball and gifted Caen the winning goal.

That 1-0 defeat left Le Guen uttering statements which became very familiar to the long-suffering Rangers supporters who had been ecstatic at his coming to Ibrox two summers ago. “We had bad luck, but we must all stick together,” he said. “We must keep believing. Things are going against us at the moment, but we must have hope.”

The question is, how long can he survive? Le Guen’s is one of the most traumatic declines of any modern European manager, having gone from messiah to arch-villain in two short years. It must be all the more galling for Le Guen to watch Lyons, the team he guided to three successive titles, and who had begged him not to resign as manager in 2005, march towards another French title. With cruel irony, Alain Perrin’s team will also arrive at Ibrox next week for their Champions League showdown against Rangers.

As trouble at Camp des Loges has flared, all eyes now are on Alain Cayzac, the PSG chairman, who lured Le Guen to Paris with relish when he left Rangers 11 months ago. Cayzac has been noticeably silent in recent weeks. On Sunday, PSG make the trip to Auxerre, and it is a match from which they must take something, otherwise Le Guen will be on death row.

Yesterday was one more dark day in Le Guen’s attempts to resurrect a once-dazzling career.