I don't see it Especially, considering that the #1 impact player on the outcome of a game is the starting pitcher. The #1 or #2 will not absolutely not be pitching on September 28th if there is any shot that a team is playing in the WC series unless they do not have the playoffs clinched..I don't care if a bye is on the line - it's not happening.
The situation is often more complex in baseball because of the amount of games - you have 3 in the last weekend compared to 1 in football, but once the playoffs are clinched, seeding is a secondary priority.
Like I said to zamb, your logic makes sense, but we can revisit this when a situation comes up. Nothing you can say will change my mind, only what the clubs actually do in those situations. From what I've observed, the don't care much about byes, seedings, etc. Obviously, they are not going to avoid them, but the number one priority is health and setting the team up for the playoffs in terms of pitching, once the playoffs are clinched.