Newcastle, having used all of their substitutes, was forced to play the final 27 minutes against Darlo with 10 men after half-time substitute Nicky Butt went off with a thumb injury.
Chris Hughton (after the Darlo game): "He has partially-dislocated his thumb which, in injury situations, is not a particularly serious thing.
"He has gone to hospital and normally what will happen is they will put it back in. It will be quite painful, but I would think he would be training in the next few days.
"He's tough boy Nicky and if anything, he would have stayed on. But we have to do things right and I am sure it will be OK."
But Newcastle have been dealt yet another blow with the news the influential midfielder will miss the start of the new season.
The 34-year-old needs surgery to repair the hand injury he suffered in last weekend's friendly at Darlington and will not be available for four weeks.
A club statement said: "Newcastle United can confirm that Nicky Butt requires an operation on the hand injury sustained during Saturday's 7-2 victory at Darlington."