Glasgow (AFP) – Celtic assistant manager John Collins heaped praise on striker Leigh Griffiths after he bagged his 40th goal of the season in his side’s 2-1 defeat by St Johnstone.

The Hoops frontman became only the eighth player in the club’s history to reach the 40-goal barrier in a season when he scored a 53rd-minute opener at McDiarmid Park on Wednesday.

Griffiths is the first player since club legend Henrik Larsson to reach that tally and Collins is delighted to see the striker thriving after initially struggling when he joined in January 2014.

“He’s an absolute goal machine. This season he’s been outstanding from start to finish,” Collins said. “He’s been consistent, scored important goals and been a constant threat.

“He’s scored all types of goals: 20-yarders, 30-yarders, headers, right-foot volleys. He’s constantly on the move and centre-halves don’t like playing against him because he’s always running in behind them.

“He makes good runs and I thought our goal was terrific. It was built from the back, played through the midfield and then Leigh does what he does best and made a run between their back two and tucked it away.

“He’s worked hard and got his reward. He’s had a wonderful season and let’s hope he continues next season and goes from strength to strength.”

Celtic made seven changes from the side that defeated Aberdeen on Sunday to clinch their fifth successive Scottish Premiership title.

Griffiths fired the Hoops in front, but their lead was shortlived as Steven MacLean took advantage of a Stefan Johansen error to dink home a 56th-minute equaliser.

A misunderstanding between Celtic goalkeeper Logan Bailly and defender Efe Ambrose then allowed Graham Cummins to give St Johnstone the lead in the 77th minute, ending a 12-match unbeaten run for the Hoops and condemning them to just their fourth defeat of the season.

“It is always disappointing to get any defeat. We didn’t want that, but we gave away cheap goals,” Collins said.

“We are disappointed but we made a lot of changes tonight. The league is won so it was important to give all the boys a game.”

Celtic will be presented with the championship trophy on Sunday when they take on Motherwell at Parkhead and Collins, who will leave the club with manager Ronny Deila following the game, admitted the occasion would be full of mixed emotions.

“We’ll look forward to it very much. It’s trophy day, so it’s important we get ready and put in a good performance,” he said.

“It is the last game for us so it will be sad walking out for the last time, but we’ve been there for a couple of years so it’s someone else’s opportunity now.”