Conversation so far:
How much success did Sean Kelly have on the grand tour?
Sean Kelly won his only grand tour and also won the points competition.
Did Sean Kelly have any failures?
Sean Kelly finished 46th in the Tour de France.
What team was Sean Kelly in the Tour de France?
The Flandria team was in two parts. Sean Kelly rode with the second section.
Who were Sean Kelly's teammates?
The Flandria team was in two parts: the strongest riders, such as Freddy Maertens, were in the main section.
How many times did Sean Kelly lose in the grand tour?
Sean Kelly won his only grand tour, over West German Raimund Dietzen and also won the points competition.
What year did Sean Kelly participate in The Grand Tour?
Sean Kelly returned in April to the 1988 Vuelta a España which started on the rugged mountainous island of Tenerife.

Question: why did he only race once?
Self-contained rewrite: Why did Sean Kelly only race once in the Grand Tour?