The 27-year-old has been ruled out until May after undergoing surgery on a thigh injury picked up in a FA Cup win against rival Sunderland earlier this month.
Joelinton is due to see his current contract at St James' Park expire in June 2025, and talks are underway over an possible extension, but Newcastle are allegedly unwilling to meet the player's wage demands.
Magpies CEO Darren Eales recently revealed that the club may be forced to sell star players as they are under pressure to comply with Financial Fair Play (FFP) regulations and the Premier League's Profit and Sustainability Rules (PSR).
Speaking about Joelinton's injury at a press conference on Friday ahead of Newcastle's FA Cup clash with Fulham on Saturday, Howe said: «It's a massive blow for us. We knew when he did the injury it immediately didn't look good.
»We didn't know he'd be out as long. He's had a stop-start season. When he is fit and firing, there's no one like him and he brings a different dynamic to our midfield. He's a leader as well. He'll be a big miss."
«He has 18 months left on his contract,» Howe added. «As his manager, I'm determined for him to stay. I love him as a person and a player, so that would be my wish, for him to sign a long-term contract.
»But of course there's more to it than that. There's Joe's wishes and what he wants. Before he signs a contract he has to be entirely happy with everything. We're not at that stage yet."
When pressed on whether Joelinton could leave Newcastle in the summer, Howe said: «I'm not a fortune teller but it's a possibility. I hope that's not the case.
»He has 18
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