Conversation so far:
What did Pedro Martinez do after he retired from baseball?
On January 24, 2013, Martínez joined the Boston Red Sox as a special assistant to general manager Ben Cherington
Did Pedro Martínez do anything else after he retired from baseball besides becoming a special assistant?
In 2015, Martínez was hired by the MLB Network as a studio analyst and also released an autobiography, Pedro, which he coauthored with Michael Silverman of the Boston Herald.

Question: How long was he with the Boston Red Sox?
Self-contained rewrite: How long was Pedro Martinez with the Boston Red Sox?