Celtic have reached such a state of acclaim that criticism has long given way to compliments in Neil Lennon's pre-match lexicon.

A run of 16 consecutive victories in domestic competitions has generated a surge of plaudits. The praise is merited for a side that was once, briefly, 15 points behind Rangers in the Scottish Premier League, and even Lennon joined in when he described his team as "devastating" after defeating Hearts on Wednesday night in "probably the best performance in my time as manager".

Lennon is wary of hyperbole, and he gently upbraided Adam Matthews for agreeing to the suggestion that Celtic might remain unbeaten until the end of the season. The manager is also uncomfortable with any parallels being drawn with the Martin O'Neill side that accumulated a British record of 25 successive league wins in 2004, a team Lennon, his assistant, Johan Mjallby, and his first-team coach, Alan Thompson, were all part of.

Yet, at a time when the Celtic defence are keeping clean sheets, the midfield is a balance of diligence and scoring ability and the forward line can be irrepressible, the tendency is to look for the secret ingredient behind this successful formula.

Yesterday's game against Inverness Caledonian Thistle was Lennon's 100th as manager and he might feel as though other milestones are within reach. The team only narrowly finished second in the league last season and made it to both cup finals, winning the Scottish Cup and losing the League Cup to Rangers. They are currently favourites to win all three competitions in this campaign.

Scott Brown, Charlie Mulgrew, Gary Hooper and James Forrest have cornered the market in eulogies of late, but the Celtic manager volunteers a ringing endorsement for Joe Ledley. The Welshman, who hit the winner in yesterday's clash in the Highlands, was the second signing of Lennon's reign, arriving on a free transfer from Cardiff City, and his combination of elegance and robustness, defensive positioning and industry, passing accuracy and scoring instincts, have all become vital.

"Fantastic. " Lennon says warmly of the midfielder. "Joe has been one of my best signings. He is a quiet lad, but the boys love him. He is very flexible in the way he plays, be it left-back or the left side of midfield. His best position is central midfield, but when we have moved him around, he just gets on with it."

As well as his flexibility, Ledley has scored six goals this season – including the winner against Rangers with a header at Celtic Park last December – having struck seven last term. At 25, he is approaching his prime, and there is every like-lihood it could be spent in Glasgow.

As a free agent, Ledley was being courted by a number of clubs in the summer of 2010, but the non-English sides benefited from the fact that they would not have to pay a development fee of around £3 million. That level of commitment is small change for most Premier League sides, and Stoke and Everton were among those keen on Ledley, along with Celtic and Roma. Lennon, in his first transfer window, made the Welshman's signing a priority.

"We had to make a really good pitch to him," he says. "It was quite a coup to get him, but the moment I spoke to him I could tell he was gen-uine and not affected by the other side of the game. He is entrenched in the club now and is in it for the long haul. I'm sure there will be a few calls about him pretty soon, but they will be quickly discouraged.

"He is one of the first names on my team sheet. Would you rather be mid-table in the Premier League or playing here where you are playing on the edge every week with a fanatical crowd shouting you on?"

The manager speaks warmly, too, of Brown and Victor Wanyama, and the sense is of him building a significant side, one that will be inspired by its surroundings. "While things are going well," Lennon says, "I don't think there are many better places in football."