Neil Lennon is disregarding Celtic's recent home drubbing of St Johnstone in the Scottish Communities League Cup ahead of tomorrow's meeting in the Clydesdale Bank Premier League.
The Parkhead side thrashed Steve Lomas' men 5-0 earlier in the month to set up a semi-final appearance against St Mirren at Hampden in January.
However, the former Celtic skipper, still basking in the glory of his side's 2-1 Champions League home win over Barcelona in midweek, remembers that Saints caused an upset when they beat the Hoops at McDiarmid Park in the SPL in September.
Asked about the recent result against St Johnstone with regards the impact it might make on proceedings at Parkhead tomorrow, Lennon replied: "It will be irrelevant.
"I'm sure Steve will have them well motivated, as we were to beat them as they had turned us over at McDiarmid Park and we will be using that result in Perth as a motivation again on Sunday.
"But we have to adapt ourselves. I want the players to enjoy the aftermath (of the Barcelona result) but it is back to St Johnstone.
"We will try to carry on and play the good football that we have been playing.
"The SPL is our priority because it is the avenue that gets us into the Champions League in the first place."
"The SPL is our priority because it is the avenue that gets us into the Champions League in the first place" - Neil Lennon
The Northern Irishman, though, believes the visit of the Perth men will be "tricky" following the "euphoria" of Wednesday night when Celtic made Europe sit up with their unlikely Group G win which left them with a good chance of making it through to the knockout stages of the competition.
"It is important that we re-focus again," said Lennon.
"The rest will be important but where the players are mentally at the minute, I don't know.
"I'm sure among the players there will be a huge dose of satisfaction and also fatigue but I will have a chat with them and see how they feel.
"But I will want to put out a strong team because St Johnstone are going very well in the league.
"We have taken one point from six in the league and so it is important that we get back to winning ways as soon as possible."
Lennon will assess skipper Scott Brown who missed the win over Barcelona due to illness.
Right-back Mikael Lustig should recover from a hip knock but left-back Emilio Izaguirre (hamstring), stopper Thomas Rogne (calf), winger James Forrest (hamstring), and strikers Gary Hooper (hamstring) and Lassad (groin) are all still out.