Manchester United manager David Moyes says he is still not sure whether he will bring any new players into Old Trafford before the transfer deadline on Monday evening.
United remain in pursuit of Everton players Leighton Baines, the England defender, and Marouane Fellaini, the Belgium midfielder, despite failing in a series of bids, while Athletic Bilbao have confirmed their £25million offer for midfielder Ander Herrera.
But Moyes, whose team face Liverpool at Anfield in the weekend's top Premier League game, said: "I don't know how busy it's going to be but it will be busy.
"It looks like the market may get busy in the next few days. I hope that we do a little bit of business, but I couldn't guarantee that."
Moyes has been chasing the Everton duo all summer, with one joint bid of around £28m being publicly rejected by the Merseyside club as "insulting and derisory".
An increased bid of £36m, while again being turned down this week, is much closer to Everton's valuation of £45m for the pair, and it is thought an adjustment of £40m would be difficult to ignore.
Everton are understood to be resigned to losing Fellaini, who is valued at around £23m, but are much more reluctant to part with Baines.
They have denied that the England left-back has asked Roberto Martinez, Moyes' successor as manager of Everton, to facilitate a move to Old Trafford.
United have been told by Bilbao president Jose Urrutia they need to meet the £30m release clause in Herrera's contract, and Moyes is monitoring the situation at Real Madrid, where Gareth Bale's impending arrival could trigger exits including Luca Modric, the former Tottenham midfielder who has been a United target previously.
On the plus side, Moyes has seen off Chelsea's attempt to prise Wayne Rooney from Old Trafford, and expects the England striker to be key to United's defence of the title.
He said: "Wayne has been a great player for Manchester United. I thought he played very well the other night (against Chelsea). He's in good condition, and mentally he's in good shape, so we'll do everything we can to keep that going."
Moyes is satisfied that United have avoided an over-demanding group in the Uefa Champions League. United's opponents in Group A will be Shakhtar Donetsk, Bayer Leverkusen, and Real Sociedad, who beat Lyon 4-0 on aggregate to reach the group stages.
United, twice winners under Sir Alex Ferguson, will open their campaign at home to Bayer Leverkusen, managed by the former Liverpool defender Sami Hyypia, on September 17.
Moyes said: "The group is okay. The last team drawn out was a difficult one, to get Sociedad who have done well in Spain. Donetsk is a long way and a difficult game but I don't think the travel is too bad. It could have been a really difficult draw, like Celtic."
Moyes has experienced only one Champions League tie previously after his Everton team finished fourth in the Premier League in 2004-5, but it did not end well.
Everton lost both legs of their third qualifying round eight years ago against Villareal, who were managed by Manuel Pellegrini, now Moyes' cross-town rival at Manchester City.
His most successful season in Europe came in 2007-08, when Moyes took Everton to the last 16 of the UEFA Cup, in which they were beaten by Fiorentina.