Need some advice on which lens would suit me more, Sigma 200mm or the Sony 250mm?

I currently have a Sigma 70-200mm F2.8 that I mainly use for sports in indoor arenas (Etihad Stadium for AFL, Rod Laver Area for the tennis), however it is a very big lens and I am going to be travelling around for 4 months soon and want something smaller and lighter but with the same focal length, would something like this lens Sony SAL-18250 DT 18-250mm f/3.5-6.3 be a downgrade on performace? Or for what I am using it for would it still be ok?