Bucks must beat Staffordshire by a convincing margin at Gerrards Cross this Sunday if they are to have a chance of qualifying for the later stages of the National Counties Trophy 50-over competition.
Bucks stand fourth of five in Group 4 but can still finish in the top two by winning their final game and hoping that leaders Wales NC convincingly defeat Dorset in the top-of-the table clash.
In the event of a tie on points, group placings are decided by nett run rate, in which Bucks trail some way behind the top two.
Only a big win over the bottom county will give Bucks a chance of getting a top-two place.
For this crucial match, Bucks make one change to the squad that lost by three wickets to Dorset in their last game. Eliot Callis replaces leg-spinner Stephen Croft, as they bid to shore up their vulnerable batting line-up. Play gets under way at 11am.
Bucks squad: T Hampton (High Wycombe) capt, E Callis (High Wycombe), A Kervezee (Halesowen), C Louth (Wokingham), C Marrow (Gerrards Cross), R Richardson (Whitburn), E Casterton (High Wycombe), E Bragg (Halesowen), M Payne (Amersham), J Rodnight (Great Brickhill), C Parsons (High Wycombe), C Haddow (High Wycombe).