Holland’s current deal with the club expires in June.
He told the South London Press: “Being out of contract does worry you as a player, especially as one of the more senior players.
“But I’m not thinking I’m coming to the end of my career, because my performances and fitness levels have been good this season.
“My ProZone stats are something I always check and I’m happy with them.
“I suppose there always is that niggling doubt in the back of your mind that you don’t know what you’ll be doing next season. Your future’s up in the air.
“But the key’s just to do your best. Your contractual situation shouldn’t really affect your form – you should be a lot more professional than that.
“But I do feel I’ve proved, if people were doubting me, that I’m more than capable of doing a job at this level.”
He added: “But even if worst came to the worst and we were relegated, I’d still love to stay here next season.
“I’ve had four good years at this club. Yes, we’re having a tough season – but it’s still a good club with good people. Players would still want to pull on a Charlton shirt and the club has established a good reputation.
“It is a big club now. And I’m playing for a new contract here. It’s a challenge, but I’ll just concentrate on the one to try and keep us up – the rest will take care of itself.”
