Conversation so far:
what was the colorado rockies about?
Looking for a veteran bat to help their playoff push, the Rockies agreed to a deal with Giambi on August 23, 2009.
was Looking for a veteran bat to help their playoff push, the Rockies agreed to a deal with Giambi on August 23, 2009. successful?
On May 19, 2011, Jason Giambi hit three home runs in one game, the first such game for him of his career.

Question: who did giambi play against that day?
Self-contained rewrite: who did Jason giambi play against when he hit three homeruns in one day?