Brendan Rodgers warned the rest of Scottish football that the best is yet to come from Celtic after they clinched their sixth Scottish Premiership title in a row with eight games to spare.
Rodgers' side hammered Hearts 5-0 at Tynecastle on Sunday, giving them an unassailable 25 point lead over Aberdeen at the top of the table.
The Glasgow giants have dropped just four points in the league in Rodgers' debut season as Celtic boss.
A first treble since 2000-01 now looks firmly on the cards for the Hoops - who clinched the League Cup against Aberdeen earlier in the season - with rivals Rangers the opponents in next month's Scottish Cup semi-final at Hampden.
And Rodgers, who has been rebuilding his reputation at the Parkhead club following his sacking from Liverpool, says his side will continue to improve.
"My job when I came in was to win it in the best way we possibly could," said Rodgers, who replaced Ronny Deila last year.
"We have had many outstanding performances but we have only just begun because there's still an awful lot of development in this team. That's the real exciting part. "Over the course of the season the players have improved tactically and they are comfortable playing in different shapes.
"But there are areas that we will improve on going forward.
"The players will improve because their awareness of the game is getting better so we play the game better.
"But I just think I need a couple of players in order to really compete at the Champions League level. That's huge for us.
"We had some good performances in there this year but there is a certain dynamism you need at that level."
- Intensity -
Following Aberdeen's 7-0 thrashing of Dundee on Friday, Celtic needed three points against Hearts to clinch their 48th top flight title.
They did so in style as a Scott Sinclair hat-trick alongside goals from Stuart Armstrong and Patrick Roberts helped them demolish Hearts.
"The win probably typified how they've been for the majority of the season," Rodgers added.
"I think it's been the hallmark of their work this season - the professionalism they've showed, the attitude and determination and style in which they've played.
"We know it was going to be a tough game but the style and the intensity of our play was admirable. To win a pressure game like that as convincingly as we did is an absolute remarkable achievement by the players.
"There has been a determination, hunger and ambition to be the very best that they can possibly be.
"We never have a lazy day in our work. The players are very focussed on a daily basis and we take that attitude and energy into the games.
"I've got a group of young players who are still developing and some senior players who are still developing and they bring that hunger into the games.
"We want to finish the season strong so that means continuing with this level of performance."
Hoops captain Scott Brown, whose career has been rejuvenated by Rodgers, savoured the seventh title of his 10-year Celtic career.
"Footballing-wise this one has definitely been top notch," he said.
"We've brought in some great players, but the gaffer has brought the belief back to everybody. We were disappointing last season but this season we've really pushed on."