Conversation so far:
What is the Borussia Monchengladbach?
he was part of the team.
Where was the team located?
European.
How long was he on the team for?
Simonsen waited for his contract to expire and moved to FC Barcelona in 1979.
did the team win many matches?
He scored the deciding goal in the 2-1 1979 UEFA Cup Final win against Red Star Belgrade.

Question: What did he do after moving to Barcelona?
Self-contained rewrite: What did Allan Simonsen do after moving to Barcelona for playing in the FC Barcelona?