NEVER mind Aberdeen chasing Celtic down to the wire. At this rate they might not even finish second.

The manner of this crushing defeat at McDiarmid Park – their third straight defeat on the road – against a St Johnstone side who have little left to play for suggested that this team which has served Derek McInnes so well over the past nine months have utterly run out of steam and inspiration.

Should Hearts beat Motherwell this weekend then the gap between the Edinburgh side in third place to the team who only a month or so ago harboured genuine hopes of winning the Premiership title will be five points with four games to go.

“The best team, the most determined team won the game," said McInnes, who admitted work still had to be done to finish second. "It was a poor night for us.

"We were dominated at both ends of the pitch. We have lost a few of that type of game this season based on a lack of physicality, size and strength. It is something I am well aware of. We need to get more size into the team."

McInnes now has to find a way of ensuring this season does not fizzle out.

"The players know who we represent in every game and they want to finish strongly. We were better in the second-half but that is scant consolation.

"We just want to make sure we win enough points to clinch second place. The players are conscientious and have done well enough all season but we have to heed this warning and recognise there is work to be done over the next few days.

"They have not switched off. I don't believe they have. We just allowed ourselves to be dominated by St Johnstone and that made the game more problematic than it should have been."

It was a night in which nothing went right for McInnes. Michael Rose was given his debut in defence and was hardly helped by his senior team-mates in a 3-4-3 system which didn’t work.

St Johnstone started (and ended) well and came within an inch of a fifth-minute goal. A fine inswinging corner courtesy of David Wotherspoon was met inside the six-yard box by Joe Shaughnessy who was unfortunate to see his powerful headed effort rattle the crossbar.

A goal for the home side had been coming long before they broke the deadlock on 13 minutes. Rose fouled Graham Cummins 25 yards from goal, slightly left of centre. Wotherspoon took the free-kick and produced a sublime curling effort over the wall which deceived Aberdeen goalkeeper Scott Brown and the ball nestled in the bottom corner.

It could so easily have been 2-0 on 20 minutes. The Aberdeen backline pushed so far up that every one of them was hovering about the halfway line, Murray Davidson spotted this and played a great ball through one of the many gaps to Chris Millar.

He looked certain to go right through on goal but Graeme Shinnie got back well which forced the St Johnstone man into an earlier shot than he would have wanted and his effort was wide. Next up was Darnell Fisher, on loan at the Perth club from Celtic who got up from right-back to hit a half-volley onto the top of the net.

Brown in the Aberdeen goal was beaten again on 34 minutes when a Wotherspoon corner, which he aimed towards the back post, was bundled home by Steven Anderson but he was to be denied by referee Craig Thomson who had spotted an infringement and blew for a foul against St Johnstone. The decision appeared to be harsh.

Aberdeen were playing so badly that they were always going to concede another, which they duly did on 37 minutes. A high, hanging ball from Tam Scobbie was met by the unmarked Anderson at the back post, he headed across goal and Steven MacLean touched the ball home from a yard. Nobody in red seemed inclined to do anything about it.

McInnes, however, had to do something and young Rose did not reappear after half-time. Barry Robson was put on as Aberdeen switched to a four-man defence. It changed nothing.

It was all too simple for St Johnstone on 55 minutes when Cummins pounced on a loose ball at the edge of the box, he squared a pass to Liam Craig who had all of Perthshire in which to operate and sent a low shot past Brown.

Fisher blew a great chance for a fourth when he ran on to a Wotherspoon pass inside the box, St Johnstone had played some great football beforehand, but he put his shot high. Again, Aberdeen did next to nothing to stop the danger. The Saints found it all so easy.

“It was an excellent performance,” said a contented St Johnstone manager Tommy Wright. “We deserved the win. We were more like ourselves and I was pleased with that. It probably could have been more but it was 3-0 against the second best team in the country so maybe that is being greedy.

“I couldn’t have asked for more. It’s easy to say these final games don’t mean anything but they are important. We are playing for pride and last season showed we are the fourth best team in the country. We want to do that again."