Extremely skilful on ball, Salah at reduced speed (3-2)
I believe the answer is:
Here is my best explanation:
'at reduced speed' is the definition.
'extremely skilful on ball salah' is the subsidiary indication.
'extremely' means to remove the middle letters.
'on' says to put letters next to each other.
'ball' becomes 'o'.
'salah' becomes 'mo' (Mo Salah).
'skilful' with its centre taken out is 'sl'.
(Another definition for slo-mo that I've seen is "Slow motion (colloq.)".)