Charlton have handed a trial to former Holland international striker Collins John.
The 23-year-old, who has two caps for his country, has been told by NEC Nijmegen that he is free to leave.
His registration is still held by Fulham, who had loaned him to their Eredivisie counterparts on the summer transfer deadline day.
The Liberia-born frontman struggled to make at impact at NEC, with the Dutch side claiming his fitness levels were not up to first team football.
Should he impress during his time at The Valley the Championship strugglers will have the option to sign John on a free transfer.
Meanwhile, Charlton have allowed Mikkel Rygaard Jensen to leave the club.
The 18-year-old was handed a two-year contract upon his arrival from Herfolge last summer, but has lasted just six months.
He is now heading back to his former employers, with the Danish outfit delighted to have the talented midfielder back.
"Mikkel was a very talented player when he left us and having seen what he has done at Charlton it's clear that he has grown even more," Herfolge manager Per Rud told the club's official website.
"We were happy to take him back when the situation appeared."
Jensen has no regrets about taking on an English challenge and believes he has plenty of positives to take from the experience.
"It was really educational to be in England," he said.
"From a personal point of view, it is good to stand on your own two feet and I am really happy I got the chance.
"I have learnt to play faster and I am stronger physically.
"It's been a turbulent time for the club, though, and there was a lot I had to get used to. I am now looking forward to playing every weekend again."