Leigh Griffiths not under-estimating Aberdeen and Celtic close in on treble.

Leigh Griffiths feels Celtic must be at their best when they go for the treble against Aberdeen.

The champions warmed up well for Saturday's William Hill Scottish Cup final by finishing the Ladbrokes Premiership season unbeaten thanks to a 2-0 win over Hearts.

Brendan Rodgers' side have beaten Aberdeen five times this season including in the Betfred Cup final but the Dons finished the term strongly with two wins in Glasgow, beating Rangers and then thrashing Partick Thistle 6-0.

Griffiths, who has lost two finals with Hibernian, said: "We are under no illusions that Aberdeen will bring their A-game. They are a really good side, and on their day they can beat anybody. But if we have a slip-up then we will have a really difficult afternoon. If we bring our A-game then we will have a really good chance of winning that cup.

"We will do everything we can to be prepared and come Saturday at three o'clock we will be raring to go.

"After the game if we do win I will be thinking, 'Thank god'. I have been to two finals already and been beaten twice, so hopefully this is third time lucky for me."

Aberdeen's Firhill win saw them seal a club record points tally of 76 but some - including Kilmarnock striker Kris Boyd - claim Celtic's feat of remaining unbeaten is down to a lack of competition.

The achievement is by no means unusual in Europe - 22 teams from 19 different countries have gone a league season unbeaten this century, including Arsenal, Porto and Juventus.

Griffiths said: I saw that from Kris Boyd in his column, he said it was the worst standard Scottish football has ever been. But I think if you look at it as a whole Aberdeen have got a really good points tally, St Johnstone playing really well, Partick Thistle playing really well, and Rangers have had their ups and downs.

"But it was all about us and what we do. Going through the whole season unbeaten is quite an achievement regardless of what league you are in.

"Everyone is allowed their opinion, he played in a good Rangers team back in the day. But we can only play what's put in front of us.

"It's testament to the boys, we have faced different challenges throughout the season and we have come through it the other end with the sun shining."

Griffiths headed his 18th goal of the season against Hearts after he was forgiven him for questioning Rodgers' decision to substitute him against Thistle in midweek.

"The boys were giving me a bit of stick after it and a lot of people on Twitter gave me abuse, but I knew the gaffer had drawn a line under it and I was glad to be back on the pitch scoring goals,'' he said.

"I shouldn't have acted the way I did, it was disrespectful towards him and my team-mates and the fans. It was a moment of madness from myself and I apologised for it.

"I got the stare of death on the bench when he turned round and that was enough to tell me enough's enough."

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