Gregg, who has already agreed terms with the likes of Michael Doherty, Mark Scoltock, Ruairi McClean and John O'Loughlin, has also been talking to a host of players.
"I have held talks with Austin, but because he's a quality striker he is also talking to other clubs, however he has told me that he will tell me his decision one way or the other tomorrow," said the 'Stute boss.
"I can also tell the supporters that I have been talking to a few other players for certain positions, which I feel we need to strengthen.
"I have also put striker Andy Crawford on the transfer list and to be honest he may not be the only player who might leave the club."
The Coleraine man also confirmed that the club will be starting pre-season training later this month, with Blue Square North side Tamworth their first pre-season outing in July.
"Everyone at the club knows how important this season is and the players are no different so I have told them that pre-season will be starting on Tuesday, June 17, that gives us a good six week's training under our belt before the season starts.
"I remember games last season, where we dropped points late-on, while having looked at Linfield, their two main characteristics is their fitness and organisation. Everyone knows they have quality players, but their fitness and work-rate is second to none, so if we can match them fitness wise that would be a good start.
"I'm also bringing in a fitness coach and hopefully by the time Tamworth come on July 15, we'll be in good shape and preparing to play a few systems."
Gregg is convinced that his players need to adapt to different formations.
"I strongly believe that my players need to be able to change from a traditionally 4-4-2 system to possible a 4-3-3 or even a 4-5-1 formation.
"It will be horses for courses throughout the year and we'll prepare different systems for different games, but the players need to be used to different formations."
Meanwhile the Official Institute Supporters club will be holding their Annual General Meeting, next Monday, June 9, at 7.30pm sharp, in the Boardroom at Drumahoe.