Pep Guardiola made two highly questionable decisions in the case of Jerome Boateng and Franck Ribery, playing both of them despite an increased risk of injury, according to this report by TZ.
Jérôme Boateng started the game against Hamburg in spite of him having major adductor pain throughout the week leading up the contest. Boateng worked intensively with the medical staff to try to get to full fitness, but as we now know, they weren't able to accomplish it, as the player will miss at least 3 months with an adductor tear as well as a muscle bundle tear after going down early in the second half despite what seemed like a rather harmless challenge by Nicolai Müller.
The site is also reporting that Guardiola went against the advice of the medical staff back in december before the Zagreb game when he played Franck Ribéry twice in four days after the former French international missed 9 months with a nagging ankle injury. While this story never made it past "rumor" when it first happened, it's interesting that it popped up again, suggesting that maybe there was something to it.
While it seems unlikely that Guardiola would risk his players getting injured/re-injured in rather meaningless games such as the ones that put Ribéry and Boateng on the shelf, it shouldn't come as a total surprise. It's Guardiola's last season in charge of the club, and I'm sure he's starting to really feel the pressure as many might say he did not live up to expectations in his first two years in charge.
Especially in Boateng's case, Bayern had come off a 2-1 loss to Karlsruhe the week before and getting his players into top form for their UCL clash against Juventus next month is most certainly a top priority. While it still wouldn't justify throwing Boateng into the starting line-up against HSV, it would at least give you some idea of where the reasoning for it came from.