Diao reportedly opened the scoring in the 18th minute, then left the pitch five minutes later after struggling to run. The forward is being assessed for a muscular problem, with Fabregas suggesting the issue may have occurred during the finish.
That timing matters. Diao had provided both movement and end product before going off, while Como were already without Moise Kean. If the injury keeps Diao out, Fabregas could lose two important attacking options at once.
The report says the club hopes the problem was caught early, but no recovery timeline has been established.
Como’s lead lasted only two minutes before Gjivai Zechiel equalised. Anis Hadj Moussa then put Feyenoord ahead, before an own goal increased the deficit. Tasos Douvikas’ stoppage-time strike came too late to change the result.
That sequence underlined the difference between a promising start and sustained control at Champions League level. Como had begun the campaign with a 4-1 home win over RB Leipzig, but the Rotterdam setback exposed how quickly momentum can disappear away from home.
The report says Fabregas felt Como improved during the final half-hour, yet Feyenoord deserved the win. Martin Baturina and others also found it harder to escape pressure than they typically do in Serie A.
Fabregas has reportedly accepted that some selection decisions may have been wrong as Como attempt to manage three competitions. Diao’s fitness will now make that balancing act more difficult.
A muscular injury may be short-term, but the next assessment will shape Como’s attacking plans and rotation. Their response in the next league fixture, and in the next Champions League assignment, will show whether Rotterdam was a setback or the start of a wider squad problem.