Hartson and Larsson played together for Scottish giants Celtic from 2001 until 2004.
Ibrahimovic, who will become a free agent at the end of this month when his current contract with Paris Saint-Germain runs out, was emerging at Ajax at the time.
The Sweden international is now reportedly on the verge of joining Manchester United.
According to The Guardian, the former Barcelona striker’s agent, Mino Raiola, has reached a deal with United over the star’s salary, and talks will now take place between Ibrahimovic and the club’s new manager Jose Mourinho.
Hartson has revealed the discussion he had with Larsson at Celtic about Ibrahimovic.
“I know quite a lot about him actually, I remember Henrik Larsson telling me about him at Celtic,” Hartson told Metro.
“He said: ‘There’s a young player coming through who is 17 years of age in Sweden and he’s going to be something special.' And that was Ibrahimovic. He’s gone on to become something really special.”
Ibrahimovic is one of the best players on the planet and remains a world-class striker even at the age of 34.
In fact, the former Juventus and AC Milan striker is one of few players who have become better with age.