The Nigerian forward has impressed in his brief time at Old Trafford since joining the club on loan in January, but his deal expires next month.
United were hopeful of extending that date further to allow for the delay in completing the Premier League season due to coronavirus.
United were weighing up signing Ighalo on a permanent basis this summer after being pleased with his impact.
That could prove to be the only way of keeping the 30-year-old at the club, with Shenhua holding out for a £20million transfer fee.
With the transfer window not due to open until the end of the season, signing Ighalo would likely require his loan to be extended, as well as a pre-contract agreement to be in place.
He would then be able to officially complete the switch when the window reopens in the summer.
One positive of that outcome for United would be that if could ward off any interest in the striker from elsewhere.
Newcastle are now said to be interested in Ighalo’s services if their proposed takeover goes ahead.
Ighalo would no doubt prefer to stay at his boyhood club Man Utd than move elsewhere, but the consortium behind Newcastle’s takeover bid could blow any competition out of the water financially.
Shenhua have already made efforts to try and tie Ighalo down to a longer-term contract, having offered him a £400,000-per-week deal in March.
Regardless of whether he signs a new deal or not, Shenhua are not in immediate danger of losing Ighalo, who is still under contract until 2022.
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