Krul usurped Harper following the departure of Shay Given to claim the No.1 shirt but an elbow injury sustained on international duty with Netherlands has ruled him out of the next Premier League fixture.
Magpies boss Alan Pardew has described Harper as 'unlucky' in recent years, as the longest-serving player at the club prepares to don his gloves once more.
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"In training he's been as good as I've seen him since I've been here and there's every chance he will play against Everton.
"We still have Rob Elliot as well, who unfortunately got injured and has only just returned. In some respects it probably comes too soon for him to be given a considerable opportunity. There's a good indication that Steve will play."
Harper, 37, has extensive experience of playing for Newcastle, having made over 150 appearances for the club. He has also seen 12 different managers take charge of the Toon, including Sir Bobby Robson, Kevin Keegan, Graeme Souness and Alan Shearer.
The current incumbent, Pardew, appreciates what Harper brings to the table, stating: "He's certainly played in more European and Premier League games than I have so he's got vast experience and we're going to need that in this period.
"He's important in the dressing room, he's seen the situation arise and knows what to do and what not to do when you're either winning or losing. That experience will be very important [while Krul is unavailable]."
Harper has been on Newcastle's books since 1993, during which time he has been loaned out to six different clubs - including a brief spell with Brighton and Hove Albion last season.