Owen was not fit for action on Sunday as the Magpies continued their impressive pre-season form with a comfortable 2-0 win over Juventus.
Despite speculation over the England striker's contract - there has been talk of a £9.5million get-out clause ever since he swapped Real Madrid for St James' Park - former chairman Freddy Shepherd insists interested parties would have to rush through a deal by Tuesday to activate the sale.
Allardyce expects arrivals and departures before the transfer window closes. But if Shepherd is correct, Owen - who has yet to prove his fitness since succumbing to his latest injury problems - looks set to start the season as a Newcastle player.
Shepherd told Radio Five's Sportsweek: "Without it [the clause], I don't think we would have done the deal - but it is only valid until July 31.
"After that, he would have to stay for another year unless it was in the club's interests to let him go."
Shepherd, replaced at the United helm by city lawyer Chris Mort following Mike Ashley's takeover, believes Owen now has the chance to repay a debt to the club after a string of injuries which have limited him to only 13 games since his arrival.
"I think he owes Newcastle quite a lot, I'll put it as bluntly as that," said Shepherd.
"I think he's played more times for England than he has for Newcastle, so I think he owes the supporters quite a lot."
Allardyce, meanwhile, looks well served up front - Albert Luque taking his recent record to three goals in two outings with a penalty to open the scoring against Juventus, Obafemi Martins set to stay at the club, Mark Viduka poised to link up with his new team-mates soon and youngster Andy Carroll also netting against the Turin side.
But he is still looking to recruit players, with at least one more defender and a possible replacement for Kieron Dyer - who is attracting interest from West Ham and Tottenham - in his sights.
The match against the Claudio Ranieri's visitors ended with a host of youngsters on the pitch - including Darren Lough, Charlie Barnett, Matthew Pattison, James Troisi and David Edgar - but Allardyce is determined to avoid putting too much pressure on inexperienced players.
"We are still very much in the transfer market. If we started the season with the same side that ended this match it would be a disaster. We're still after experienced, quality players," he spelled out.
"They played well. But it doesn't change anything - we're still light on numbers."