Saints manager Owen Coyle has already laughed off suggestions that they are playing the SPL leaders at the right time, however.

Lennon said: "I don't think it's ever a good time to play Celtic. Everyone is saying we are stumbling to the line but I keep looking at the league and we are still 13 points clear, so I'll take that every season.

"We have played okay in a lot of games but haven't had the results. We played okay against Motherwell, we are back on the horse again, it was a big win for us and sets us up nicely for Saturday.

"But I'm sure St Johnstone are relishing playing against us, semi-finals are always difficult games.

"It's an important competition, it's a huge game for us, we've got a cup final at stake."

The midfielder may feel Celtic's dip in form has been exaggerated but he is in no danger of underestimating St Johnstone.

The Perth side have already beaten SPL sides Rangers, Falkirk, Motherwell and Dundee United this season, while Hibernian needed extra-time to beat them in the CIS Cup semi-finals.

Lennon is full of admiration for Coyle, whose side cut the gap at the top of the First Division to five points with a 2-0 triumph at Gretna on Saturday.

"It's a tricky tie for us, St Johnstone have upset a few Premier League teams already," said Lennon. "They had a great result at the weekend at Gretna, putting the promotion party on ice.

"It's a dangerous tie for us and we'll have to be at our very best.

"Owen was a quality player, he knows the game, he was a very good centre-forward and has a good football brain and obviously he is transferring that to the management.

"I'm sure he hasn't got a great budget but he is in the semi-final of the cup and they did well in the League Cup as well.

"They beat Rangers at Ibrox, for a First Division club that is a fantastic achievement.

"I'm telling you, it's going to be a tough game for us on Saturday. I know that and I'm sure the rest of the players know that."