With the start of the campaign less than three months away, no fixtures or dates have as yet been released by the England & Wales Cricket Board, aside from the confirmation that the Vitality T20 Blast Finals Day will be on July 16 at Edgbaston.
The competition is expected to be played in one block leading up to that date.
Northants are preparing for their return to the top flight of the LV= Insurance County Championship for the first time since 2014, and although they do know who they will be up against, they have no idea when or where those matches will take place.
“It is quite frustrating, because it is normally November time when the fixtures come out and it helps you plan things,” said Sadler, who is undertaking his first pre-season as County head coach after replacing David Ripley.
“There are different reasons as to why it has been delayed, but it is frustrating.
“We all want to see them, you get excited by the fixtures and you plan your diaries a little bit and you plan you work it back and look at pre-season tours and pre-season friendlies, and how they all fit in.
“We are all kind of in the same boat that we want to get things in, but we can’t at the moment.
"It is frustrating but it is out of our hands, we can’t control it, and we have to just worry about what we can control.”
The ECB have made no official announcement when the fixtures will be announced, but it has been reported that it will definitely not be until after the conclusion of the fifth Ashes Test in Australia that started today, and could be as late as the last week in January.
Northants will compete in division one of the LV= Insurance County Championship, as well as the Vitality T20 Blast and Royal London One Day Cup.
The One Day Cup is expected to be staged at the same time as The Hundred competition, which will return for its second season.
Division One teams: Essex, Gloucestershire, Hampshire, Kent, Lancashire, Northamptonshire, Somerset, Surrey, Warwickshire, Yorkshire
Division Two teams: Derbyshire, Durham, Glamorgan, Leicestershire, Middlesex, Nottinghamshire, Sussex, Worcestershire.