The Danish centre-back was dropped to the bench as manager Steve Cooper handed a Premier League debut to summer signing Caleb Okoli.
Since the start of last season, the defender had played every game in which he has been available.
Vestergaard told Danish media he was in great shape and ready to play as he looks to fight to win his spot back in the side.
“It is a completely natural thing that there is competition for the places and that the coach has a choice to make. I was available and I am available. I am both when I start and when I am on the bench.
“But I'm in good shape. I actually feel better than ever before. I don't have an answer to your question in relation to the explanation, but I am available.”
Conor Coady is also now fully fit which means the Danish star will have a lot of competition for his spot as Leicester face Crystal Palace this weekend.