Precisely one hundred days after Dublin City proudly proclaimed the appointment of Roddy Collins in a press release bearing the headline, "THE ROD IS BACK" the club's players and officials were left stunned by their manager's decision, not only to leave, but to defect to relegation rivals Shamrock Rovers.

Neither Collins nor Rovers chairman Tony Maguire could be contacted yesterday but the club issued a short statement confirming the Dubliner's appointment just a matter of hours after City's managing director had been told the former Bohemians and Carlisle United boss was leaving the club with immediate effect.

Collins last night told RTÉ news: "I left them in a very good position with a very strong squad of players."

Collins made no mention of his imminent departure for Rovers when he spoke to Dublin City's chief executive Ronan Seery at 9.30 yesterday morning to tell him he was leaving. Seery only heard about the Rovers job on the phone from a third party an hour later.

Clearly still shocked by the departure of a man he had steadfastly defended in the face of criticism recently, Seery admitted he had had to phone Maguire to confirm the news.

That call, as might be expected, appears to have become a little emotional. "It's amazing stuff," said Seery. "I woke up this morning thinking about the Drogheda game which is the biggest in the club's history, as, to be fair, all the recent games have been. I hadn't the slightest notion something like this might happen but when I met with Roddy at half nine he said he was going.

"I don't even want to talk about him now," he added. "I can't, to be honest, but what I would say is that for Rovers to do this to another club is staggering. Who would behave like that? They must be the lowest board in football anywhere in the world."

Club captain Tony O'Connor, though less shaken by the news, admitted to being deeply surprised by the timing of the move. For some time it has been apparent that overhauling Rovers is City's only chance of avoiding the drop and the matter could well come down to the last game of the season when the two sides meet at Richmond Park.

"Well, I suppose the first thing you'd have to say is that you wouldn't expect somebody to do something like this on the day of a game," said the defender. "And certainly the fact that he has gone there would go against everything that he has been preaching to us since he came here about unity and all the rest of it.

"So far I've only talked to one other player but I'm sure everybody in the squad will be shocked. All you can do, though, is to hope that it will help us in some way, that we can draw some inspiration from it all and go on and send Rovers down."

There was said to be some disquiet within the playing ranks at Collins' new club, too, yesterday with the new man's reputation for ruthlessly overhauling squads he inherits prompting fears he would initiate a clear-out at the earliest opportunity.

At Dublin City there was a string of arrivals and departures after his arrival although it did little good as the club's results have been worse since his arrival than under predecessor John Gill who departed in July after becoming frustrated with his inability to do the job given the resources available.

He is not in a position to change a great deal at Rovers for the moment given there is only three weeks of the season left and the deadline for signing players has passed but almost all of the club's players will be out of contract when the campaign ends and the fear is that most will be shown the door.

Collins' agreement with Rovers apparently involves a two-year contract although it is reported this has not been signed and it is not clear whether his long-term future at the troubled southside outfit is dependent on him consigning his former employers to the first division.

Rovers face two other Dublin derbies, with Bohemians this evening and St Patrick's Athletic next weekend, before the game against City and Collins arrives at a time when the team has gone 14 matches without a win. Given the task facing their rivals, however, Rovers have always been in a the stronger position of the two clubs and could quite feasibly stay up without taking another point.

When asked about the prospect of top-flight survival only two days ago Collins expressed confidence that it could still be achieved. It seems he may have been referring merely to his own prospects rather than those of Dublin City.

Dermot Keely has taken temporary control at Dublin City.