R' Moshe Feinstein forbids going to stadiums to watch sporting events all year round.
But some rabbis rule differently than R' Feinstein. See, for example, this link, as well as the ruling of R' Sheinberg quoted near the bottom of this link.
According to those rabbis who permit attending sporting events during the rest of the year, would you also be allowed to go to a sporting event (e.g. soccer, basketball, baseball) during Sefirat Ha'omer?
I know that you are not allowed to listen to live music or go to plays or things of that sort, but I am unsure if going to watch a professional game would be allowed or not (for example, MLB, NBA, NFL, or NHL).