There's an other way of looking at it. Now in teams sports this may not be as true as in one on one "combat sports' but in boxing, kickboxing, and MMA there is a train of thought that as a big fight nears you actually want to start using weaker sparring partners, not better ones. The point is to build your fighter extreme confidence. As a trainer I actually practiced this method and liked it. Now I'm sure it's a little different in a team sport, but I could see staying healthy and having tons of confidence as being positives for a team heading into the playoffs.

It some point in training you wanted your fighter to be "challenged" but you didn't want that happening too close to the fight night. Anyway, just a little psychological trick that is fairly common among fight trainers. May or may not translate into team sports.