The former striker turned down the chance to become an aide to the controversial director of football, but has backed him to do well in his role due to his contacts in the game
The two worked together at Wimbledon, Luton and Nottingham Forest, but Harford decided against working as Kinnear's aide on Monday.
Kinnear was controversially appointed director of football in June before blasting fans who had criticised him and the Magpies board, but Harford insists owner Mike Ashley has made a wise decision.
"I think any person who goes into any club with have doubters," he told Sky Sports. "One thing Newcastle United have got is a really top football man who has got connections all over the world, as he said he can talk to anyone, and has got a good relationship with most people in football.
"I'm positive this is a good move by Mike Ashley."
It emerged on Sunday that Harford had been approached to leave Millwall, the club he joined in June, to work alongside Kinnear in the north east, but he believes he is better suited to working on the training ground with the Lions than in the day-to-day running of a club.
"The job on offer was to be assistant to the director of football, just to work alongside Joe on scouting and recruitment," he continued. "Just helping him mainly, just being an aide to him. I've got a lot of respect for Newcastle United, I know the passion that these people have for their football club, so it was a tough decision for me.
"You never know in football, you never close any doors. I like to be on the training ground, but who knows, I'm a lifelong friend of Joe's. I had a fantastic meeting with Mike Ashley and Joe Kinnear and Graham Carr, we spoke about the football club, they didnt have to sell Newcastle United to me, I know the club inside out."
"It was very tough. Obviously with Joe Kinnear and Newcastle United as a football club it was an honour and a privilege to be offered a role.
"It was a tough decision for me to make, I had been in talks with millwall over a period of time, I spoke to Joe over a period of time. Millwall offered a position that I felt best suited me, and I felt Newcastle wasn't the best timing for me.
"It was a great opportunity to come to Millwall. The Newcastle situation was a really tough one not to take, I just think I'm a bit too young to sit behind an office desk, I should be on the training ground."