Maloney admitted he was unsure of the welcome he would receive following his return from Aston Villa, who he joined in January 2007 after contract talks with Celtic chief executive Peter Lawwell stalled.

But the Scotland international was afforded a huge cheer when he came on for the injured Jan Vennegoor of Hesselink during Saturday's 3-0 win over Falkirk.

And he further endeared himself to the Celtic support with an inspirational show in the Clydesdale Bank Premier League win.

Lambert said: "I didn't think there were doubters, to be honest. Everybody knew what they were getting.

"Maybe Shaun had a little bit of trepidation himself about how the Celtic fans would take to him.

"I just thought if you sign for a club, you tend to think everybody will be behind you, and him being the player he is, I didn't think there was ever going to be an issue." Lambert believes Maloney's return has given Celtic a huge boost ahead of Sunday's Old Firm derby at Parkhead.

But he feels both squads are looking in rude health, after Rangers signed midfield quartet Pedro Mendes, Steven Davis, Maurice Edu and Aaron Niguez, and Celtic added Dutch defender Glenn Loovens as well as Maloney.

The influx of flair players has given Rangers fans hope, after the despair which followed Carlos Cuellar's departure to Villa in the wake of the embarrassing Champions League defeat by FBK Kaunas. "I think the Old Firm game will be a lot, lot closer than people were thinking a couple of weeks ago," said Lambert, who was promoting Setanta's coverage.

"Rangers have made terrific signings in Mendes and Davis; Celtic have got a really strong squad of guys who were there last year.

"Brining back Shaun gave them a major, major lift. So I think it will be a decent game."

However, Lambert does not subscribe to the theory that the outcome of the match will give the winners a significant psychological advantage in the SPL title race given its particularly early slot in this year's SPL fixtures calendar.

"If you lose it affects you probably for a week until the next game," said the former Celtic skipper who won the Champions League with Borussia Dortmund and four Premier League titles during his time at Parkhead. "The beauty about the Old Firm is you don't have time to dwell on it, you have to pick yourself up and go again.

"You still have almost 40 games to play, so whatever happens in this one won't have any significance whatsoever to where the league is going to go."