Name a Rugby Union forward (6)

I believe the answer is:

rupert

I'm a little stuck... Click here to teach me about this clue!

Here is my best explanation:

'name' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?

'a rugby union forward' is the wordplay.
'a rugby union' becomes 'ru'.
'forward' becomes 'pert' (I've seen this before).
'ru'+'pert'='RUPERT'

Can you help me to learn more?