Here is a good article on historical DL data. In 2016 players were placed on the DL 561 times or about 19 times per team and is increasing each year.
http://www.conteanalytics.com/blog/t...-disabled-list
Here is the number of players on the DL by month in that 2017 Quick start i referenced above.
April: 71
May: 102
June: 94
July: 81
August: 96
September: 102
October: 14
The total is 560.
Now maybe the length of the injuries is too long which is a little hard to measure in the game, but the frequency of injuries actual is realistic.