Highly-rated teenager Aaron Sexton says he is ready to give full-time rugby his undivided attention after leaving athletics.
Iain Henderson takes over from fellow Ireland forward Rory Best as skipper of Pro14 side Ulster.
Ulster flanker Marcell Coetzee is named in the South Africa squad for Saturday's Rugby Championship match against Australia.
Ulster host Ospreys at Kingspan Stadium on the opening night of the 2019/20 Pro14 season on Friday, 27 September.
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Rory Best says he didn't want to join the ranks of great Ulster players whose final home game was a defeat.
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