Derby County attacking midfielder Ivan Calero has been training with Burton Albion and could join on loan.
The 19-year-old Spaniard has made three substitute appearances this season, scoring the winner in the League Cup against Charlton Athletic in August.
Meanwhile, Rams boss McClaren has paid tribute to defender Shaun Barker, who has returned to training after nearly three years out with a knee injury.
"He has battled and never gives in," McClaren told BBC Radio Derby.
"He has always been around the place and has kept his spirits high.
"To see Shaun train with the first team is nothing short of a miracle. When I first came, the boy couldn't walk. I thought he would be lucky to walk again without a limp.
"He trained with us and did ok. That's character, and epitomises what every player should have. He could have given up but he wants to get back playing football and he has taken giant strides this week."