Newcastle United manager Eddie Howe has revealed that Joelinton is ruled out for a minimum of six weeks with a thigh injury.
The Brazilian sustained the problem towards the end of the first half of the Magpies' 3-0 victory over Tyne-Wear rivals Sunderland in the FA Cup third round last weekend.
Joelinton was assessed at half time and came out for the second half, but the versatile midfielder was unable to continue and hobbled off just two minutes after the restart.
Speaking at a press conference on Friday ahead Newcastle's Premier League clash at home to Manchester City on Saturday, Howe confirmed that Joelinton is facing a lengthy period on the sidelines.
"It isn't good," the Magpies boss told reporters. "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.
"It's a difficult place to get an injury hence the reason why he's out. He's very disappointed and we've been trying to pick him up. Joey's injury is a freak one where he's standing up and been caught off balance."
Howe has also revealed that fellow midfielder Joe Willock is making progress in his recovery from an Achilles injury, but he is not quite ready to return, while Elliot Anderson remains out and will have another scan on a long-term back issue next week.
"They're not expected back any time soon," said the Newcastle boss. "Elliot is continuing his rehab from a stress fracture in his back. It's been a difficult injury to manage for him and he's not been very active for a long period of time, he's trying to let his back heal.
"I think he has another scan next week so hopefully that'll give us good news and he can start to build up his work.
"With Joe Willock, he's improving. He's building up strength in his Achilles and feeling better, but still not running."
Furthermore, Howe has confirmed that Harvey Barnes is closing in on a return after around four months out with a foot injury, while Callum Wilson (hamstring) is targeting a return for Newcastle's top-flight clash with Aston Villa on January 30.
"Harvey is getting closer," Howe added. "He hasn't trained with the group but he's been running on the grass, had his boots back on and kicking balls around. We're pleased with his progress currently but he still has a long way to go.
"We're well aware of what Callum's problem is and the timescale on it. We're hoping that he can be back in and around for the Aston Villa game, that's what we're looking at. Obviously, if it takes a bit longer, we'll take that time, but we don't see it being a long-term issue."
Meanwhile, goalkeeper Nick Pope and winger Jacob Murphy remain sidelined as they continues to recover from shoulder injuries, with the latter believed to be the closest of the two to making a comeback.
Discussing how injuries have affected his Newcastle squad this season, Howe said: "We haven't wanted to focus on the injury situation because there's not much good to be had from talking about it consistently or highlighting it.
"Unfortunately for us, any injury we've picked up hasn't been a one-week or two-week injury. Everything's been six to eight weeks, at a time where we can't afford it."
Newcastle head into Saturday's Premier League contest sitting ninth in the table, 11 points behind fourth-placed Arsenal and third-placed Man City. body check tags ::