Ousmane Diomande joins Nottingham Forest for €40m

BBC reports that Nottingham Forest have secured the services of defender Ousmane Diomande from Sporting CP for a reported fee of €40m. The transfer is confirmed and adds depth to Forest's back line ahead of the new season.

The move has been tracked by sixteen outlets across the market, confirming the fee and the completion of the deal. Onside’s model values Diomande at €6m, indicating the club is paying substantially above the internal estimate.

Onside’s confidence in the data is rated at 100%, and the fee‑vs‑value read flags an overpay relative to the model valuation. The club will need to integrate the player quickly to justify the premium paid.