The Foxes had all but agreed the loan switch on deadline day but the Premier League club were unwilling to let Bruma leave until the signing of David Luiz was completed.
That was finally wrapped up with just minutes to spare before the 11pm deadline and, when the papers were filed for Bruma`s deal, they arrived too late with the powers that be.
Speaking after Tuesday night`s 1-0 win at Sheffield United, Eriksson said: "It was very close but I think there was a lot happening at Stamford Bridge between 10pm and 11pm.
"What I heard is the clearance from Benfica (for Luiz) came just three or four minutes before 11pm. They wouldn't let anyone out until they got someone in, and I understand the difficulties.
"But we will see in one week's time if we are going to do anything or not. It might still be possible."