Alan Pardew's side took until late April to confirm their Premier League status for another campaign, with injuries to the likes of captain Fabricio Coloccini, Yohan Cabaye, Chiekh Tiote and Krul himself all coming at key stages of the season.
Newcastle secured a surprising fifth-placed finish 12 months earlier - above Chelsea in the standings - and Krul is confident his side can begin to reach those heights again.
| NEWCASTLE LATEST
|66/1||Papiss Cisse is 66/1 with BetVictor to be the Premier League top goalscorer next term
"But we had so many injuries. It was just ridiculous; me, Colo, Yohan, Steven [Taylor], Hatem [Ben Arfa] ... we all missed important parts of the season and I think that definitely contributed."
Newcastle enjoyed a European run in the Europa League last season for the first time in six years, and Krul feels the demanding fixture schedule may have taken its toll on an insufficient squad size.
"Being able to train for a full week will make a big difference," he added.
"We won't have any Europa League games next season and that does have an impact on the training as well as the freshness of the squad.
"Next season we'll be right up there, I have no doubt about that."