It took the Annan Athletic players several minutes to leave the field.

They deserved to dwell upon the moment, since they deserved this victory, and they celebrated exuberantly in front of the small number of away fans. The Rangers support had mostly left by then, but the few who remained clapped the visitors up the tunnel. Their warmth was genuine, and perhaps it helped them to cope with the consternation their own team had caused.

For all that Annan – a part-time side which had not won in any of the seven games since Jim Chapman took charge, and which had lost 5-1 away to Montrose – played crisply and with belief, Rangers were abject. Their flaws were collective, since no individual distinguished himself with an acceptable display, but they are also recurring. This performance was not an isolated aberration.

The glory belonged to Annan, who scored through Ally Love's backheel and David Hopkirk's brave header. For Ally McCoist, the Rangers manager, this display raised only haunting questions. His team are 17 points clear of Queen's Park, who have a game in hand, and it is inevitable they will win the league, but context is a diminishing comfort.

Rangers have taken refuge in the disruptive effects of last summer, the registration embargo, the small squad, that contains a number of raw, developing youths, but how are those factors reflected in the team's persistent faults? In truth, they are not. It is March, Rangers play part-time teams, and the wage bill is the second highest in the country. McCoist should still have a team that is capable of overcoming their Irn-Bru Third Division opponents.

"The players know that was unacceptable," said McCoist. "You can sometimes take a defeat if you have been unlucky, but that wasn't the case. It wasn't good enough. We'll go over the game in detail, however painful that might be, find out what want wrong and try to rectify it."

This is the significant point. Although McCoist has been let down by the players he signed last summer, the team should still be performing better. It was evident that the gameplan was not working against Annan, but no changes, either in personnel or positions, were made at half-time. Too often this season Rangers have been sluggish in the first half, or until falling a goal behind, before the team is finally roused to play at a high tempo.

At Ibrox in particular, opponents should be put under intense pressure straight from kick-off, because the weaker sides will then fold. Rangers have generally failed to take advantage of this psychological edge.

"We tried to be positive," said David Murray, the Annan striker. "We had to get through the first 10, 15 minutes. It's the first time I've played in front of that many people but once you get over the initial shock you settle down. We took the game to Rangers. We had composure and we passed it around."

Nobody will understand better than McCoist the scrutiny and pressure that comes with being at Rangers. He is acutely aware of the deficiencies of his team, and it will infuriate him that this side continues to let him down. Even when Andy Little pulled back a goal with a close-range header, Rangers could not overwhelm their opponents, and there was half an hour remaining.

This spell in the lower leagues was a chance for Rangers to implement a football philosophy, of investing in the scouting network and youth development programme to ensure that when the club finally returns to the top flight, its foundations are strong. McCoist has spoken of the difficulties in signing players and the need to focus on gaining promotions, but the journey back should be based on a sustainable football model, one that identifies promising talent, buys it cheaply and sells at a premium.

These are defining months. The side needs to improve, despite its limitations, and the football department needs to be maximised. "Everybody is playing for their future, including the coaching and management staff," McCoist said.

He will need to demand better, if only to match his own ambitions.