I was totally upset as well; it makes no sense whatsoever - here is a link.
A few seasons back, EA Sports started disallowing injured players in all online H2H games. If you want to move an injured player into the starting spot, you’ll have to wait until the end of the NFL season, after the Super Bowl. Madden 18 is no different. In case you haven’t been able to keep up with all the latest injuries, the pros at Madden School have put together a list of injuries with the biggest impact in Madden 18.
https://www.madden-school.com/injuries-with-the-biggest-impact-in-madden-18/
