The Black Cats now appear a little light of options at the back following the departures of left-back Denver Hume, as well as centre-backs Frederik Alves and Tom Flanagan.
Sunderland do have players returning from long-term injuries, including Luke O’Nien and Niall Huggins, yet it’s unclear when they will be available.
Another option in the short term is to explore the free agent market.
We have taken a closer look at what the Black Cats could do:
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1. Put more faith in Arbenit Xhemajli
Despite Batth's arrival, Sunderland are a centre-back down compared to the first half of the season, following the departures of Alves and Flanagan. Xhemajli has just recovered from a long-term knee issue and has made just one senior appearance this season, yet he may be needed if Sunderland are hit with a couple of injuries. Photo: JPI Media
2. Wait for Luke O'Nien to return
The versatile midfielder had surgery on his shoulder in November and has started running again at the Academy of Light. It looks like O'Nien could return before the end of the season which would give Sunderland an extra option at centre-back or at full-back. Photo: JPI Media
3. Winston Reid
After 11 years at the club, Reid left West Ham last summer. The 33-year-old helped Brentford win promotion to the Premier League last season, making 11 appearances during a loan spell during the second half of the campaign. Photo: Robbie Jay Barratt - AMA
4. Andre Wisdom
A versatile defender who has played across the back four. The 28-year-old made 38 Championship appearances for Derby last season but wasn't offered a new deal in the summer. Photo: Malcolm Couzens