The promising Liverpool talent had to be stretchered off the pitch during a 1-1 draw against West Ham United in the Premier League 2.
No date has yet been set for his return, with the club confirming that the 18-year-old will now take part in a rehabilitation programme under the supervision of the club’s medical staff.
Stewart has received messages of support and one came in from Liverpool legend and current Rangers manager Gerrard.
Under-23 boss Lewtas is thrilled with the messages the youngster has received, but while dubbing them unbelievable, is not surprised due to those who have sent their best.
“I know how strong Layton is as well”, Lewtas told his club’s official site.
“He will work as hard as he can to get back to full fitness as soon as he can, but there will be no timescale put on that.
“We will just give him all the support he needs.
“Layton has also had some fantastic messages from the likes of Sir Kenny Dalglish and Steven Gerrard, which is absolutely unbelievable, and you expect nothing less from people like that.
“It will mean a lot to Layton and messages of support like that will help him along the way.”
Stewart grabbed 15 goals in just ten appearances for Liverpool Under-18s prior to his injury, while he also netted twice in eight Under-23s matches.