Yeah you are almost certainly right. Contreras came in as a defensive replacement for Miggy immediately following the inning, and from rewatching that inning, I know Grant Dayton (lefty) was warmed up and ready to come in. Another factor in walking Cogs was that he was 8-17 lifetime against Blanton heading into that AB and I don't think Dayton was quite ready at that point. But regardless of everything else, the Intentional Walk was primarily to get Chapman out of the game. Just a pretty big gamble to put the go ahead runner at third in the 8th inning, especially when you are walking a guy who wasnt on a major league roster 2 months before and you are pretty much guaranteed to not get a good matchup with the next hitter.