Despite attracting interest from a collection of clubs, The Lions have only received one firm offer for the player - rumoured to be around £400,000 - from Championship new boys Peterborough United but the deal fell through after Whitbread failed to agree terms with The Posh. However, Jackett knows it is only a matter of time before he departs.
"We have had no other bids for Zak this summer, apart from the Peterborough bid," Jackett told Sky Sports. "He is a very good player, so if he does end up staying at Millwall then that would be terrific, but at the same time he has stated his wish to leave and that looks inevitable.
"It's difficult when a player shows a desire to be elsewhere and players often get what they want these days, but we'll have to wait and see if anyone else comes in for him."