David O'Leary, himself a champion of the teens and early 20s, joined the 8,631 spectators who constituted London Road's biggest crowd of the season. However, if the Leeds manager had come to assess Peterborough's Matthew Etherington as a possible successor to Harry Kewell on his left flank, or the prospects of Fry's other prized asset, Simon Davies, becoming the new David Batty, he may have left pondering the talents of Barnet's Marlon King and Danny Brown.
Both are 19. King, picked up free from Dulwich Hamlet reserves by the man now occupying Fry's old managerial chair at Barnet, John Still, finished clinically twice in three minutes to overturn the early lead Howard Forinton had given Peterborough. His first full game this season, against Carlisle five days earlier, also brought him two goals.
Brown, for whom Still paid Leyton Orient a small fee after spotting him "playing like a man amongst boys" in a junior match, was the driving force in a Barnet midfield which proved too numerous and powerful for Peterborough. Mark Arber, 22, and Robert Sawyers, 21 last week, were also outstanding.
Barnet's only promotion to the Second Division, in 1993, coincided with Peterborough's best-ever position of 10th in the First. Neither could sustain their progress. Peterborough fell so deeply into debt that they had no option other than to produce their own players, while Barnet all but folded amid the financial debris left by Stan Flashman's chairmanship.
Still, coincidentally a former "Posh" manager, neatly encapsulated the current disparity between the clubs. "Peterborough will be very disappointed if they don't maintain their form, with the support and resources they have," he said. "We've got the smallest ground and the lowest crowds in the whole League but, if we stay injury-free, we've got enough quality to be there or thereabouts."
Last season, when Barnet finished 16th compared with Peterborough's ninth, they lost both fixtures by a 14-3 aggregate. It is not that players like Etherington, 18, Davies, 20, and left-back Adam Drury, 21, have stopped progressing; theirs were among the better home performances, and the beautifully balanced Etherington almost saved a point late on with a drive which Lee Harrison brilliantly tipped over. Yet Still won the tactical dual with Fry, whose insistence on playing two touchline-hugging players left Davies overworked and overrun in the centre.
Another cause for concern for Peterborough, who have taken only two points from their last three matches, must be the state of their pitch. As befits a club saved by the founder of Pizza Express, Peter Boizot, it has the consistency of an American Hot plastered with Parmesan, which will hardly help Davies or Etherington as winter kicks in.
Peterborough's woes were complete with news of Rotherham's last-minute winner at Carlisle, which took the Yorkshire side into third place, and the advance of Darlington and Northampton to within a point of them. With only three clubs automatically promoted, spending capacity is likely to be a more significant factor than useful potential.
Darlington, bankrolled by a millionaire owner, may be the best-placed contenders in that respect. Peterborough might have to dig deep into Boisot's pizza dough, while Barnet are at last venturing modest sums in the transfer market under a chairmanship of Tony Kleanthous.
It seemed strange on Saturday, seeing Fry's hangdog expression after Peterborough's first home defeat, to remember that he gave Barnet 15 years of his life. Not just any old service, either, but marking the pitch on Christmas Day, paying the wages from his own pocket and the small matter of two heart attacks.
Ken Charlery has made the opposite journey but still lives in Peterborough after no fewer than three spells with the club. The visitors' veteran striker believed Fry's gruff exterior masked an enduring affection for Barnet. "He's always at our games. I think Barry has feelings for Barnet just as I have for the Posh."
Two together, to use a term from Mr Flashman's ticket-broking trade, would answer the Millennium prayers of both men.
Goals: Forinton (9) 1-0; King (60) 1-1; King (62) 1-2.
Peterborough United (4-4-2): Tyler; Scott, Edwards, Wicks, Drury; Farrell (Green, 68), Davies, Castle (Shields, 68), Etherington; Clarke, Forinton. Substitutes not used: French, Rea, Griemink (gk).
Barnet (3-4-3): Harrison: Heald, Hackett, Arber; Davidson, Doolan, Brown, Sawyers; King, Charlery, Currie. Substitutes not used: Wilson, Searle, McGleish, Strevens, Naisbitt (gk).
Referee: M Ryan (Preston).
Bookings: Peterborough: Clarke. Barnet: Davidson.
Man of the match: Brown.