Michael Ledger enjoyed a winning start to his loan spell at Hartlepool United but Max Stryjek suffered a hamstring injury on his Accrington Stanley debut.
The injury sustained by the promising Sunderland stopper is being assessed but he could be out for up to two months.
Stryjek was replaced in only the ninth minute of their hard-fought 2-1 derby win away at Morecambe in League Two.
On Stryjek's injury, Stanley boss John Coleman said: "He’s damaged his hamstring. We don’t know yet, but it could be six to eight weeks out.
"That’s a blow because we’re back to square one of only having one senior goalkeeper. We’ll have to try and address that this week."
There was better news for Ledger, the 20-year-old was named in the starting line-up for Hartlepool United's 3-1 win over Maidstone United at Victoria Park.
Ledger impressed on his debut at centre-back, playing the full 90 minutes as Pools secured back-to-back wins in the National League.
Stryjek, though, is now facing a lengthy spell on the sidelines. He had been looking forward to his loan spell after the move was confirmed on deadline day.
The 21-year-old has been a regular for the Under-23 side but is yet to make a first team appearance for the Black Cats.
He moved out on loan to play regularly at League Two Accrington, who beat off competition from elsewhere to sign him on loan for the rest of the season.
Speaking ahead of the game, Stryjek said: "This is my first opportunity to be around the first team of a League Two football club and I’m looking forward to it.
"It’s going to be a great experience for me to come here and I can’t wait to meet the lads and everybody here at Accrington.
"I’m expecting a huge challenge, it’s going to be faster and more physical and I’ve got to make sure that I’m ready for that."