Newcastle boss Eddie Howe admits Joelinton is facing six weeks out.
The midfielder has been hit by a quad injury suffered in the FA Cup win at Sunderland.
Howe said: "It isn't good. It is an injury that will see him miss a minimum of six weeks, it is a real blow for us.
"He is such an important player. He has a problem with his tendon in his quad. He is very disappointed, he wants to play and do well - we have had to try and pick him up. He is our midfield driving force, it is a big blow."
He added: "We're really stretched in attacking and midfield areas and that's inhibited our players from resting and bringing new players on to help with rotation.
"In an ideal world given the freedom to act, we'd have brought players in already but we're not in that situation because financial fair play is a problem for us. So, we're having to navigate around that.
"It's already a problem we've been dealing with but we're trying to manage through it."
