Depends on his health, which imo is the only driving factor behind his bad offensive year. Defensively, he seems to rate in the upper quarter of qualified 1st baseman this year, so I wouldn't really call him poor in general.
If his health issues really turn out to be chronic, that deal is going to look very, very bad. If he figures out how to manage them, he'll likely return into the 3.5 to 4 WAR range.