Competition for places has increased after the Magpies' summer spend.
Summer signing Wiljnaldum has occupied the number 10 role in the main for the Magpies this season - a position which many view as de Jong’s best.
The former Ajax man endured a torrid first year on Tyneside - making just five appearances in an injury-ravaged campaign - but has returned to fitness this season.
Implementing both creative players could prove difficult but McClaren is adamant both can be included in his first XI.
“I have no doubt that they can play together,” said the Newcastle boss.
“I think whatever the balance of the team will be - it’s not there yet - and in my head there’s still one or two, three little things that need to be improved upon before it will be there.
“But once the balance of the team is sorted and the squad’s fully fit, with everyone fighting for a place, both De Jong and Wijnaldum could definitely play together.”
Including both Dutchmen in a starting XI alongside the likes of Florian Thauvin, Moussa Sissoko and Aleksandar Mitrovic would be an attacking side, to say the least.
Newcastle have shown improvement defensively this season but scoring goals is where the problems lie for McClaren’s men and a move to a more attacking set-up could be an attempt to rectify that.