Too soon to tell, they said.
However, after the events of the past few months, when Lendl helped Murray win his first Grand Slam and an Olympic gold, the influence of the former world No 1 on the Scot has become more obvious and naturally the expectations have shifted up a level.
Having shaken off the rust in his first match against unheralded Australian John Millman, Murray improved with every match at the Brisbane International where he was due, in the early hours of this morning, to play Bulgaria's Grigor Dimitrov in the final. Murray won the event in 2012, making it the one that kicked off a year to remember for the man from Dunblane.
Murray was chasing his 25th title but the first since following up that Olympics triumph with victory at the US Open, and as such was aiming to make a statement as he heads into the Australian Open, which begins a week tomorrow. Rafael Nadal is still out, seven months after his last match, with his knees not yet 100% and the after-effects of a stomach virus leaving him under prepared. So Murray will go into Melbourne as second-favourite behind world No 1 Novak Djokovic but above No 2 Roger Federer.
His liking for hard courts and his past record in Melbourne – twice runner-up and a semi-finalist last year – as well as his efforts in New York four months ago, mean many are tipping him to win back-to-back slams.
Murray is wary of the hype, but after another good December of work in Miami, he knows he is in good shape.
Lendl arrived in town in time to see Murray battle past Denis Istomin of Uzbekistan in the quarter-finals and shrug off a slow start to reach the final when Japan's Kei Nishikori retired in the semis with a knee injury.
In Lendl's pomp, "also-rans" like Millman and Istomin were wiped off the court with disdain; now the strength in depth on the men's tour is such that if a top player is not focused from the start, upsets can happen.
"It was different back in his day where they could kind of cruise the first couple of rounds," Murray said of Lendl's vintage. "It's so, so different nowadays."
Murray has been quietly satisfied with his performances in Brisbane, especially with his improvement from match to match. One of the things Lendl has been stressing is the need to be 100% ready every time he steps on the court and, although he has yet to hit full throttle, the work in progress is progressing well.
"It's a long trip to get over," said Murray, who spent Christmas Day with his family at home in Scotland before heading to an exhibition event in Abu Dhabi. "It takes a week or 10 days before you're feeling perfect. But I've served well for the majority of the tournament and I've moved better with every single match."
Murray will have been thankful that Brisbane has avoided the worst of the heatwave that has swept through Australia this week, as was Serena Williams, who swept to title No 47 with a 6-2, 6-1 demolition of Anastasia Pavlyuchenkova of Russia.
Williams and Pavlyuchenkova are stable-mates in the Mouratoglou academy and trained together in Mauritius in the off-season before arriving in Brisbane. The Russian beat Petra Kvitova and Angelique Kerber to reach the final, but was second best throughout against a dominant Williams.
"Today was really good," said Williams, who is the overwhelming favourite to win her sixth Australian Open title. "I'm in a really calm place and not panicking, I'm not overthinking it and not just blasting every ball.
"I was looking at a lot of old matches on YouTube and I feel I'm playing some of my best tennis. I want to play better still, and I've always felt I could play better."