Taylor, the 2014 Commonwealth Games gold medallist went pro with former WBA world featherweight champion McGuigan’s Cyclone Promotions in 2015.
And the Norther Irishman said he knew Taylor was the real deal from the moment he clapped eyes on him, immediately setting himself a challenge of moulding the Prestonpans puncher into a future world champion.
Under the tutelage of McGuigan’s trainer son Shane, Taylor hasn’t been tested in any of the 12 wins on his record and has fought at iconic venues including the MGM Grand in Las Vegas and New York’s Barclays Centre.
Taylor, pictured, takes on the formidable Postol (29-1) at Glasgow’s SSE Hydro on Saturday 23 June, with a shot at the WBC world super lightweight title later this year at stake.
McGuigan said: “The Scottish fans have been great for him but anyone who hasn’t seen him yet should snap up a ticket because he’s going to be so big that I can’t say for definite he’ll be back on a bill here any time soon.
“My advice would be to catch him while you can because Josh is going to go global. If he continues to progress, we’ll be taking him all over the world.
“We have a duty to him to do whatever is best for his career – both in a sporting and a financial sense – and that’s likely to mean that he’ll be fighting in lots of different countries as a world champion.
“I firmly believe this bout will be a tipping point for Josh. Not only will a win guarantee him a shot at the WBC title, it will raise his profile because beating someone as good as Postol will let everyone else realise just how good he is.
“He’s already fought in Las Vegas and Brooklyn and the Yanks just love him because he’s an all-action guy.”
McGuigan added: “He’s an explosive kid but it’s about technique as much as it is about power. He’s learned to be patient and to take that extra half-second to set himself before he gets his shots off because it’s been explained to him that he’ll get much more weight behind his punches if his stance is correct.
“That might sound obvious but it also takes cojones to do that in the heat of battle. Josh has them and he’s proved it.
“You look at his professional record and he’s stopped 11 of his 12 opponents up until now. That tells you something.
“Viktor Postol is a top-quality opponent, better than anyone else that Josh has met so far.
“But I don’t just think he’ll beat Postol – I think he’ll stop him. But the fact we’re putting him in with Postol this early shows you the faith we have in Josh.”