Translation:They are professional soccer players that play twice a week.
Not to be picky, but it should say, "They are professional soccer players who play twice a week." "Who" should be used for people instead of "that," which would have been fine if it had been "soccer teams...."
I think you are right. If you hadn't said it, I would have. Have a lingot.
The English option here solid is actually incorrect and an extremely common error made by Israelis: it is the over use of the present progressive case, when simple present is required. In this case it should have been "...play once a week," instead of "...are playing once a week." Present progressive should be used only in a currently occurring event, not something that generally occurs...