"I am training very hard to get fit. Obviously I would love to play in the Premier League but I would not want to play for someone who could be relegated.
"I would go to a Championship club who has ability to go up and who is playing for something."
Hasselbaink was released by Charlton at the end of last season, following The Addicks's relegation from the Premier League.
Allen reportedly pulled the medical because he had requested the Dutchman undertake a month-long trial before signing a deal.