The English midfielder has been in scintillating form since arriving from Chelsea on loan in the summer.
But Agbonlahor wants the club to see how the season plays out before committing to a permanent deal.
He told Football Insider: "There's no rush. I think at the moment they've got him on loan for the season, they'll see how he does all through the season and then judge the situation at the end of the season.
"It might be something they want to make permanent at the end of the season.
"I'm sure there will be a big fee because Chelsea will value him and let's not forget he's a similar age to Jack Grealish and if he can keep producing his current form Chelsea will definitely want a high fee.
"Chelsea might even want to bring him back in their team. I think we've just got to enjoy him while he's here and try and get the best out of him."