The 23-year-old needs surgery on a foot injury, and is likely to be out until late March 2019.
After Hearts boss Craig Levein revealed the extent of the injuries suffered by Ikpeazu and defender John Souttar, the former Cambridge United striker tweeted: “Totally shocked to be honest. “Thanks for all the messages. I’ll work hard to come back as soon as possible.”
Ikpeazu has scored four goals in ten appearances for the Jambos since his summer switch from England’s League Two.
He has been key to Hearts’ early season form, but came off worse in a challenge with Motherwell goalkeeper Trevor Carson during the 1-0 win at Fir Park in mid-September.
Levein said: “Uche will be out for five months as well by the looks of things. This problem we’ve had with his foot we’ve managed to finally get to the bottom of. ~ “It’s a really obscure problem which needs an operation.”