The 18-year-old defender, who can play either as a centre-back or right-back, has represented Wales at youth level and could be set for a return to his home nation in the coming weeks.
The Manchester Evening News reports Denham is training under the watchful eye of Blueirds boss Neil Harris, but that no firm decision has yet been made over his future.
Denham only played one game for United's Under-18s last season, instead playing much of his football for an Under-17s side. His contract was due to expire in June as a second year scholar, though United made the decision to keep all players aged 18 and under contracted until December amid the financial impact of the coronavirus pandemic.
Denham, however, is free to talk to other clubs and go out on trial.