Lang was eyed as one of Europe's most exciting young talents in 2019 as he scored a hat-trick on his first Eredivisie start for Ajax.
The then 20-year-old was given the golden opportunity by Ten Hag but the pair eventually fell out and verbally clashed during a match.
Ten Hag commanded instructions on the touchline but these were dismissed by Lang, who was then sold to Club Brugge in 2021, where he launched an x-rated rant at his teammates.
He now plays for PSV Eindhoven and featured in the Netherlands' 4-0 Nations League win against Hungary on Saturday night.
It was Lang's first international appearance in over a year but it's clear that Rafael van der Vaart and Marco van Basten rate him highly.
READ MORE ON LIVERPOOL
Darwin Nunez spotted celebrating in ex-Everton defenders face
Liverpool cult hero exiled at Serie A giants forced to stay due to tax reasons
The Dutch legends also believe he is better than fellow winger Gakpo, who was close to joining Ten Hag at Manchester United.
"Gakpo is really an amazing player, worldwide, Liverpool... Noa Lang of course. Then you have a problem," Van der Vaart said on Ziggo Sport via VoetbalPrimeur.
"I think Noa Lang is better than Cody Gakpo," Van Basten said, with Van der Vaart agreeing when he replied: "Me too.
"If I look at potential, talent. But Gakpo is further. How do you deal with that as a coach?"
Most read in Football
Ipswich chief reveals Premier League clubs tried to sign Kieran McKenna this summer
How Man United could line up against Ipswich as Amorim to drop three stars in first game
Frank Lampard in advanced talks for Championship job that Ruud van Nistelrooy applied for
Harry Kane statue hidden away for five years finally unveiled - and fans are in disbelief
Ruud Gullit disagreed with them though as he said: "I don't think Noa Lang is better yet, you can't say that."
He added: "Gakpo has also proven it, come on. Noa Lang better? You can't say that. Gakpo is much further ahead, you know."
Gakpo became a summer transfer target for United in 2022 after he scored 21 goals and assisted another 15 for PSV in the season prior.
He added another 30 goal contributions in the following campaign and scored in all the Netherlands' group matches at the 2022 World Cup.
United reignited their interest ahead the 2023 January transfer window, but their rivals Liverpool signed him for an initial £35million.
Ten Hag therefore missed out on his man, who revealed that he spoke to his compatriot about a potential move to Old Trafford.
"It was the summer before," Gakpo told Sky Sports. "I was in contact with the club and the manager, he's Dutch so I spoke to him as well.
"At the end of the day it fell through, that's it, and in the winter Liverpool came. It was the best decision for me."
Gakpo has since made 96 appearances for Liverpool, scoring 29 goals and assisting another 11 across all competitions.
The 25-year-old has enjoyed a strong start to life under Arne Slot this season as he already netted six goals and assisted a further two.