Barnes, who was signed prior to the arrival of manager Dean Saunders, had also been offered a move to rival Championship club Burnley.
Left-back Ilunga made 15 appearances during his three-month loan stay with Rovers but is now looking to find a bigger club during the January transfer window.
His departure will be a heavy blow to Rovers who also lost left-back George Friend to a serious knee injury against Barnsley.
With Pascal Chimbonda and Tommy Spurr still out through injury, Saunders has a severe shortage of options for today’s FA Cup third round tie with Notts County.
In attack, however, he is finally able to call upon the services of Habib Bamogo and Mamadou Bagayoko after a two-week delay in obtaining international clearance.
Amid speculation surrounding the future of both Billy Sharp and El-Hadji Diouf, the new strikers could have a major role to play between now and the end of the season.
Saunders said: “The fans will like Bamogo. He is sharp and makes good runs. He works hard, plays with a lot of enthusiasm, and has looked really lively in training.
“Bagayoko is a different type of player – a big, strong, more robust player, with more experience. He’s been around and played at the highest level, although both have played in the Champions League.”
Bamogo, 29, is a Burkino Faso international, released by Greek club Panetolikos, who has spent the majority of his career in French football with clubs including Montpelier, Marseille, Nantes and Nice.
Bagayoko, 32, is a 6ft 3in tall Mali international, freed by Greek club Giannina.
Saunders confirmed that former Liverpool striker Diouf had still not extended his deal beyond January and Sharp was the subject of a failed £2m bid from Leicester City this week.
Rovers start today’s game against League One Notts County as favourites but Saunders will take nothing for granted.
“If you look at the league ladder, they are not far behind us,” he pointed out. “It’s not going to be a pushover and I’ve told the players that if we go in with the wrong attitude we will lose. I’ve got to pick what I think is my strongest team and I don’t have the luxury of being able to tinker and then think we can win.”
Former Bradford City defender Damion Stewart could make his debut for County after leaving Bristol City.