In sport, a number of games can be nervous! (8)
I believe the answer is:
nineties
'games can be nervous' is the definition.
I can't judge whether this definition defines the answer.
'in sport a number' is the wordplay.
I cannot really see how this works, but
'in' is found in the answer.
'number' could be 'i' (I is an example) and 'i' is present in the answer.
The remaining letters 'netes' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for nineties that I've seen before include "19th century's "naughty" decade" , "Last decade of century" , "possibly last period of life" , "Time" , "Previous decade" .)