A week on from the fanfare of the news that England all-rounder Willey will return to Northants on a four-year contract from next season, the 32-year-old captains Yorkshire in a crucial Vitality Blast clash at the County Ground (start 6.30pm).
Northampton=born Willey returns to lead the Vikings after a stint in the Netherlands with England, where he shone with the ball as Eoin Morgan’s side claimed a 3-0 ODI series win.
And although he will once again be a Steelbacks player in 2023, Sadler knows all too well that Willey will be determined to get one over his future employers at Wantage Road in what is a massive match for both teams.
A Steelbacks win, and they will be all but assured of a place in the North Group quarter-finals – a Yorkshire win and Northants could find themselves slipping out of the top four, with the Vikings leapfrogging them in the table.
It could be seen as something of an awkward situation for Willey, but Sadler expects the player to take it all in his stride and give everything to the Yorkshire cause.
"David is professional, and we spoke about this," said the Northants head coach.
"He has still got a job to do, he is still employed by them, and I am sure he will be trying to win the game.
"Such is life, and he doesn't start with us until October.
"It is still professional sport, he will be going out to win and try and smack it, but hopefully we can get one over on him."
While Willey makes his return to the Vikings ranks for the trip to Northampton, his England team-mates Dawid Malan and Adil Rashid will not be involved.
Malan has been ruled out due to an Achilles injury, while Rashid has been given permission to make the pilgrimage to Mecca.
He will miss the rest of Yorkshire's Blast campaign as well as England's forthcoming white ball internationals against India