Every team hopes to come through their preseason with no major injuries, but fortune has not favored D.C. United this year. Setting aside knocks and visa issues that have kept multiple players out of significant chunks of this crucial period of the season, United is facing an injury that we’ll likely be talking about all season. Paul Arriola was substituted early in Saturday’s preseason win over Orlando City, and the Washington Post’s Steve Goff has reported that the team suspects he has suffered a major knee injury (MRI results are, as of this writing, still pending).