United, who are due to play Kitchee FC in the stadium on Monday, have taken the decision after the torrential rain in the region over the last few days.
"Manchester United, Kitchee and the Hong Kong Football Association have reluctantly made the decision to cancel the open training session, planned for tomorrow (Sunday) evening at the Hong Kong stadium," said a statement on behalf of the club.
Manager David Moyes expressed his concerns about the state of the pitch on Friday and there must now be a real danger the match will not take place.
Tottenham were able to complete their Asia Trophy third-place play-off against South China on Saturday, but heavy rain fell towards the end of the game, leaving obviously sodden patches.
Manchester City beat Sunderland in the final, with the atrocious conditions contributing to a missed penalty by Edin Dzeko and an injury to Matija Nastasic.
The state of the pitch was also blamed for an ankle injury suffered by Spurs defender Jan Vertonghen during their 3-1 semi-final defeat to Sunderland on Wednesday.
"The pitch has suffered from torrential rainfall in the last week, as well as staging a number of games in a very short space of time," continued the United statement.
"Wednesday's matches (Sunderland vs Tottenham, Manchester United vs South China) had their kick offs delayed, only proceeding after being shortened to 40-minute halves.
"The weather has continued to present problems for the pitch and the first consideration of both the HKFA and the club has to be the safety of the players in such conditions.
"The club has consulted with the Hong Kong FA and has also taken advice from Kitchee.
- Sports & Recreation
- Manchester United
- Hong Kong Football Association