Disjoint paths in tournaments

Given k   pairs of vertices (si,ti)(si,ti)(1≤i≤k)(1≤i≤k) of a digraph G, how can we test whether there exist k   vertex-disjoint directed paths from sisi to titi for 1≤i≤k1≤i≤k? This is NP-complete in general digraphs, even for k=2k=2[2], but for k=2k=2 there is a polynomial-time algorithm when G is a tournament (or more generally, a semicomplete digraph), due to Bang-Jensen and Thomassen [1]. Here we prove that for all fixed k there is a polynomial-time algorithm to solve the problem when G is semicomplete.