It does not increase as such. Why? Because during those periods, I have also observed that the game gives at least one yellow card for most of the matches played. Even for the latest case here, I got 1 yellow card in most of the matches played in and around where the injury occurred. Oh, and the number of yellow cards does not reflect to the style of play at all, that is whether you use easy tackling, normal tackling or hard tackling in a particular game. This is another 'football' nonsense in this game.
Suppose that you don't get any yellow cards, still the increase in red packs is non-significant compared to the amount required to heal all the injuries happening. 14 packs are required to heal a player that suffers an injury of 4 days and, 15 packs are required to heal those that suffer injuries of more than 4 days. Just see how many injuries are there in this game that are in the 4-12 days range. Do the calculation yourself, and see how much red packs are needed to heal all those injuries.
Red packs cannot be saved in some situations, even if you have good squad depth and cover for each position. Why? Some times the 'thing' targets players that cover a similar position, leaving the user no other choice than to heal at least one player or sell one player and buy another one. Even if one player is sold and an other is bought, the newly bought player gets injured too. This is not coincidence. If you see the first few posts in this thread, you will see that STs were targeted. It has even happened for GKs too as shown in two of the posts in this thread. By the way things have been going, I suspect that some things have been programmed to occur as such in this game so that the user has no other choice than to buy tokens or complete offers or there are malfunctions or flaws, or it could be a combination of both.
You can do little as a manager to stop those injuries and also to stop those yellow cards. Most of it has been programmed to occur in this game; if not, then there are flaws in this game concerning those things. The only ways to get out of many of those situations is to either buy a lot of tokens to turn into packs or complete offers; also a user cannot keep on buying and selling players just because of injuries. For users like me, we have no choice but to either buy tokens or suffer significant disadvantages as there are no offers can be completed for us. But, everything has a limit. I think what has happened has gone over the limit. I call this 'extortion'.
Anyone agrees or not, what I have said is based on a lot of observations.
'T11 is a football management game'. No, it is far from being a proper football management game. The most appropriate term would be: Top Eleven is a football management game made mostly based on the business sides of view.
To those users that come and try to justify the bad things occurring in this game: you will not see it the way they are until you yourself have become a victim of at least one of them.