The Citizens face off against the Reds in a game that could decide the fate of the Premier League title.
City trail by six points at the top of the table, and they know that getting a positive result at Anfield on Sunday is vital.
"I don't know right now," said the City manager to reporters.
"It's a muscular problem. It's not big, but he didn't feel comfortable and that's why we decided to make a substitution, but honestly right now I don't know."