Bellamy was no stranger to big-money transfers during his own playing career, with clubs including Newcastle United, Blackburn Rovers, Liverpool, West Ham United and Manchester City splashing millions on the former forward, who scored 19 goals for Wales over 78 appearances.
“Once you move from a different scenario, a different club, sometimes you hit the ground running, but sometimes it takes longer,” Bellamy said.
“I remember [former Arsenal and France winger] Robert Pires for a whole season was a waste of money, next one he goes and wins player of the year… it works that way at times.
“He’s [Johnson] young and I believe all we’re seeing now is just what his talent is allowing. It was going to happen.”
Johnson’s attacking output for Wales – with three goals in 30 caps – on the face of it is modest, but he has already become a key part of Bellamy’s fledgling tenure as Wales manager.
Bellamy praised the Spurs attacker’s all-round contribution in the first two games of his era, a goalless home draw against Turkey followed by a 2-1 win in Montenegro.
Further Nations League games await away to Iceland on 11 October and home to Montenegro three days later, with Johnson named in a 25-man squad notable for the inclusion of midfielder Joe Allen after the 34-year-old’s decision to come out of international retirement.
But while Bellamy is delighted to regain the experience of Swansea City’s Allen, the manager is as enthusiastic about the youthful potential of Johnson.
The Wales boss has no doubt the Spurs attacker’s talent will shine through eventually with more goals on the international stage, but equally values Johnson’s all-round contribution and tactical awareness.
“I’m fully aware of his ability going forward, I’m sure we all are. You can’t hide that ability and obviously Spurs invested heavily in that ability,” Bellamy added.
“But what really impresses me with him is the team comes first, his work-rate for the team, and I love that, it’s so important and how we set out, it’s the team.
“And that came from the Turkey game, there were one or two instances where he was getting back at the right moment, sensing danger, and that’s incredible. For me, that’s a brilliant game.”
Bellamy says Johnson’s importance is underlined by the faith his managers have in him.
“I’m fully confident of him in that final [attacking] third; it doesn’t always work on that day, you can have a little bit of form but that class will come out on top in the end,” he added.
“Would I pick him tomorrow? Of course. Does Ange [Postecoglou, Spurs manager] pick him every game? Of course… and I believe we recognise what he’s able to do for the team.”
While Bellamy says he was largely unaware of Johnson’s social media problems, he said that players should do “what you feel is best for you”, but agreed that the decision to ‘unplug’ can be “sensible”.
“Honestly it’s a world I don’t live in, I’m not old fashioned or anything like that, I just don’t see that world,” Bellamy said.
“I completely believe what works for you works for you, I don’t get involved in any other part of it.
“I’ve always tried to move myself away from that because I believe it allows me to be fresh on what I see, so I don’t get side-tracked here, I don’t get moved here.
“Because my mind – the over-thinking part of my world – will go into a complete and utter meltdown, so I try and move that completely away.”
