Dike left the team’s game away at Ipswich on Saturday in tears on a cart after going down hurt 10 minutes after being introduced as a substitute.
West Brom said it would “provide Daryl with all the care and support he needs to return to full fitness later this year” after the diagnosis of a rupture.
He previously suffered an injury to his left Achilles in April 2023, which he only returned from in January this year.
“Unfortunately I have been injured again,” Dike wrote in a post shared on X, formerly Twitter.
“Over this past day, I have been trying to wrap my head around the situation and I honestly still can’t, nor do I think I will be able to for a while.
“One thing I quickly realised however is how blessed I am to have so many supporters around me… The things that I have seen have filled my heart and my spirits so much. I have been brought to tears numerous times.”
Dike has played 10 times for the USMNT, scoring three goals, with his last appearance coming against El Salvador in March 2023.
“As many of you know I have been injured multiple times and it has made it easy for me to think negatively,” Dike added later in his statement.
“Luckily this support has pushed many positive thoughts back in.”