Ireland captain Caelan Doris has been ruled out of the Nations Championship Southern Series along with Tommy O'Brien.

Leinster retain United Rugby Championship after battering Bulls but Caelan Doris an Ireland injury concern Leinster retain URC title with 36-7 victory over Bulls at Croke Park; Tommy O'Brien, Rieko Ioane, Jack Conan, Sam Prendergast and Harry Byrne score tries with fly-half Prendergast producing a man-of-the-match perf…