John Mousinho’s men surrendered position for all three of the League One side’s goals, while they also conceded in the opening 90 seconds of each half.
Thomas Waddingham came off the bench to reduce the deficit in stoppage time with a header from John Swift’s cross, but it couldn’t mask a poor showing.
And here are our Pompey player ratings...
13. Portsmouth. Fans and players arrive ahead of the Pre-Season Friendly match between Wycombe Wanderers and Portsmouth at Adams Park, High Wycombe, UK on 25 July 2026.
Adrian Segecic chats to Ibane Bowat and Rocco Shein before the Wycombe game. | Stephen Flynn/ProSportsImages
14. Arvin Appiah - 5
(Replaced Jordan Williams on 46 mins) Awful mistake from throw-in to set into motion the build up for the second goal. Came in at left-back and ended up on the right flank. | Dan Minto
15. John Swift - 6
(Replaced Rocco Shein on 46 mins) Provided the cross for Thomas Waddingham's consolation header. Always looks capable of making things happen. | Simon Roe/ProSportsImages
16. Zak Swanson - 6
(Replaced Harvey Blair on 61 mins) Welcome return to action after undergoing knee surgery in April. Slotted in at left-back | Getty Images