The Whites have just splashed the cash to sign Joel Piroe from Swansea City and are now also bidding for Genk attacker Joseph Paintsil.
A midfielder is also on the agenda, with Leeds pushing for a £5m deal to sign Amiri from German club Bayer Leverkusen.
Amid the frenzy of transfer activity, Leeds remain keen on signing O’Brien from Nottingham Forest.
O’Brien is a long term Leeds target and the club are again thinking of adding him to the mix at Elland Road.
The 24-year-old is on the books at the City Ground for a further three years, but has failed to win over boss Steve Cooper.
He had a spell on loan in the United States at DC United earlier this year.
O’Brien has not turned out for Forest yet in the new season and all eyes will be on whether Leeds do make a bid for him.
