The former Barnsley defender had joined on a short-term deal last season, and featured a number of times under Ryan Lowe.
Diaby now strengthens the Preston backline for the foreseeable future after the departures of Sepp van den Berg and Paul Huntington in the centre of defence.
The Senegalese defender took time to step up, gain match fitness and get a chance with Preston after having not played a game for close to two years after receiving a ban from football.
Diaby was quite emotional in his first start for the club at home to Bournemouth and it clearly meant a lot to him to be back on the football pitch.
The fans have been behind Bambo as it is nice to see someone so passionate about playing, and in his seven appearances last season there was plenty to give encouragement that he can be an important part of the squad for the next two years at least.
Still young at 24, Diaby will be keen to settle down now, and let his football do the talking.
Speaking to the official website Ryan Lowe was happy with his attitude and thinks there is plenty more to come from him. “Bambo’s been a credit to himself and to us ever since he came through the door, so we were keen for him to stay with us.”
“His attitude’s been absolutely spot on, and we feel there’s a bit of work that can be done with Bambo as well, he’s one that we can teach and get better.”
With Lowe keen to play three defenders at the back, there may be another one on the shopping list, although Jordan Storey is returning as well, and will be keen to nail down a place in the side after an impressive loan spell last season with League One side Sheffield Wednesday.
With a busy summer ahead for Preston, this will be the first of we hope a few signings that will be announced early on, which will allow a return to pre-season with the majority of transfer business done.