His main two targets would seem to be Malcolm Christie from Derby and Muzzy Izzet from Leicester. Both teams have now been relegated and will find it hard to hold on to their top players.
One report suggested that Boro would make a £5m bid for Christie this week, if Derby were relegated this weekend.
McClaren could also attempt to bring Izzet to the Riverside in a £5m deal, just months after the Turk turned down the chance to join Boro, in favour of helping Leicester in their survival battle.
Boro have been linked with Panathinaikos' Giorgis Karagounis and Ipswich's Matt Holland.
Talks are still ongoing to extend the contracts of Paul Ince and Robbie Mustoe, while other talks are still to take place over permanent deals for Benito Carbone and Franck Queudrue, who have both been on loan this season.
It was also reported this weekend that Boro have been closely monitoring the progress of Owen Hargreaves, with McClaren having excellent knowledge of the youngster through the England set-up.
Canadian-born Hargreaves has hinted that he would love to play in the Premiership but the stumbling block could be the transfer fee, his club Bayern Munich rate him in the £10m bracket.