The 24-year old arrived at the KC Stadium from Leicester City in 2011 after an initial loan with the Tigers but could be sent to Forest for the 2013/14 season.
Forest boss Billy Davies has seen two bids for Leicester's Wes Morgan rejected and is keen to bring a new centre-half to the City Ground.
"We're making extremely good offers and we're certainly not chasing unrealistic targets," Davies told the club's official website.
"We know that there will be other negotiations for other players that will take a bit of time but there is a great effort here to conclude deals very quickly.
"All we can do is continue to ask the question and continue to put what we feel are very good offers into these clubs. Anybody that suggests that these targets are not possible are looking in the wrong direction.
"We'll keep doing what we can to convince other clubs that we mean to do some sensible business and we'll keep trying to bring players to this football club."