Right-arm seamer Yusuf, 27, recently took 26 wickets in seven games in his domestic first-class competition for Lions in his best-ever season.
With South Africa batter David Bedingham suffering a fractured toe against Warwickshire, Yusuf can play as a second overseas player alongside Australian Brendan Doggett.
Ball, 34, who played four Test for England, has not played a Championship game since last August, while right-arm fast medium Blatherwick, 26, played three times for Lancashire in Division One last season.
Durham are ninth in the Championship after one draw and two losses in their three games.
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