The 20-year-old, who is currently on loan at Aston Gate, has been offered a new deal by the Hammers and Millen is waiting to see how those talks progress.
"I've been pleased with Jordan and he is in my thoughts," Millen told the Bristol Evening Post.
"But I don't want to be disrespectful to West Ham, because he is still their player. We will have to see what division they are in next season, because that will have a big bearing on what happens.
"West Ham are still negotiating with Jordan and his agent and I'm not sure what the future holds just yet.
"I will have to wait until the end of the season, see what they do with the lad and have a discussion with them then."