Jock Brown was the Celtic general manager between 1997 and 1998, and to this day believes prudence is key to any successful transfer window. 

The former commentator served in Glasgow's east end at the beginning of Wim Jansen's single but successful season as manager at the end of the last millennium, when players such as Henrik Larsson and one-time UEFA Champions League-winner Paul Lambert joined the club at a pivotal time in its history.

Overseeing Celtic's transfers, Brown played an important role in the club's league title-winning 1997/98 campaign – when Celtic halted Rangers' domestic dominance at that time, securing their first championship of the decade in the process.

And during that spell, Brown was always cognisant of the longer term implications of spending money, no matter the circumstances or context.

He said: "I was the guy who was trying to buy players and bring players into Celtic and I know how difficult that is, what's involved in that and the complications that are involved in it all.

"People talk about backing [managers], and say 'just give him the money'. That's just utter nonsense. You have to think about the long-term welfare and good of the club.

"That doesn't just mean give them what they want. When I was there at Celtic, people spoke about wages and said things like: 'Just give him what he wants'. I remember being in the situation by being very sticky about money, as I was.

"When you're dealing with someone else's money, you need to be sticky and difficult with it, and try to curb it and control it.

"And I remember when I was at Celtic and we were recruiting heavily at that time, I remember saving on certain deals which brought in Paul Lambert."

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With Joe Hart having now officially retired, and with speculation around Matt O'Riley's future growing by the day, Brendan Rodgers already has a sense of where the Celtic squad may need reinforcing for the next Scottish Premiership campaign.

For Brown, patience and a sensible disposition are always the way forward when it comes to recruitment.

He added: "By virtue of being a pain in the neck and prudent and difficult to deal with – in the sense of not just throwing money at things – that turned out for the better [for me at Celtic].

"It's very simple to say to these things: 'OK, what do you want? OK, there you go.'

"You can't do that if you're going to be sensible, and it means you're going to get another player in, or another two players in that might make a big difference to the squad."