De Bruyne was substituted and spent the final 25 minutes of Wednesday’s 0-0 draw against Atletico Madrid in Spain with ice around his right ankle after a kick from Felipe.
Meanwhile, Walker limped off in the 73rd minute of the Champions League quarter-final second leg after rolling his left ankle and was pictured wearing a protective boot on Thursday.
De Bruyne needed stitches on his injury after the game against Atletico and neither he nor Walker were able to train on Friday.
“They didn’t train today,” City boss Pep Guardiola said on Friday. “We’ll see tomorrow but apparently it would be so close after what happened on Wednesday.”
Nathan Ake has impressed as a makeshift left-back in recent weeks but returns to center against Liverpool, with Oleksandr Zinchenko also starting.
Ruben Dias was named on the Atletico bench and is once again part of the substitutes, Fernandinho being preferred over Dori. Guardiola gives Cup keeper Zack Steffen a start at Wembley.
Starting XI: Steffen, Cancelo, Stones, Ake, Zinchenko, Fernandinho, Bernardo, Foden, Grealish, Jesus, Sterling
Subtitles: Ederson, Dias, Gundogan, Laporte, Rodrigo, De Bruyne, Mahrez, Delap, Lavia