The Israeli defender limped off with seven minutes to play in Rome after failing to shake off the knock, and he has since undergone a scan.
Celtic boss Neil Lennon disclosed the extent of Elhamed’s injury is unknown, but it seems the full-back is set to spend some time on the sidelines after his latest post on Instagram.
The 28-year-old wrote on his Instagram story on Saturday: “Bad news this morning but I will be back stronger.
“Thank God always.”
It will come as a huge blow to Celtic given how impressive Elhamed has been since his £1.6million arrival from Hapoel Be’er Sheva in the summer.
The 28-year-old has since played 13 games for the Hoops, particularly putting in an impressive shift in the 2-0 win over Rangers at Ibrox in September.
He could now miss next month’s Scottish League Cup final with the Light Blues after MailSport claimed he faces at least three weeks out.
Elhamed now has to prove his fitness ahead of the clash, but Lennon has a quality cover in Jeremie Frimpong who has been impressive since making his debut, while Moritz Bauer and Nir Bitton are also options in the position.