The Sun has reported that Lascelles is set to miss three months’ worth of action with a knee ligament injury he sustained in the 2-1 win against Bournemouth on Saturday.
Fernandez has stepped into the Newcastle starting line-up in recent weeks and has impressed supporters with his form.
The Argentine’s current deal is set to expire at the end of the season but Waugh, speaking via a Q&A session on The Athletic’s website on Wednesday, claimed that Lascelles’ setback could lead to negotiations with the ex-Swansea defender.
“Fernandez is an interesting one,” said Waugh. “The last I heard was that there was nothing imminent with regard to the Argentine, who will be free to speak with clubs abroad come January.
“His form in recent weeks has been impressive but, given that Newcastle have six senior centre-backs, I’m not sure how sustainable it is keeping them all.
“Lascelles’ injury may accelerate potential talks with him, though.”
Fernandez has proven in the last three matches that he is well worth keeping around at St James’ Park. Not only did he score in the 3-2 win at West Ham and assist a goal against Wolves, he has also been solid at the back, doing an impeccable job while standing in for the injured Fabian Schar. Newcastle have very good depth in the centre-back roles so why not keep everyone on board? Schar, Lascelles, Clark and Lejeune have all had their injury problems lately so it is good to have plenty of options available. It will be interesting to see what Bruce considers his best back-three when everyone is fit and available because Fernandez might not be in it, even though the Magpies are undefeated in league games he’s started this season. The Argentine is worthy of a contract extension, even if it is just to preserve his transfer value.