Walsh, who brings vast experience of playing in subcontinent conditions, has already begun working with the squad ahead of the global tournament, scheduled to run from February 7 to March 8 in India and Sri Lanka.
Heinrich Klaasen hammered a blazing unbeaten century as South Africa beat West Indies by four wickets in the third and final ODI to level the series on Tuesday.
Mayers finished 2/10 off four overs while Roach has 2/28, leaving West Indies trailing by 153 runs heading into Wednesday's critical fourth day at the Sir Vivian Richards Stadium.
New Zeland have been in great shape, sitting pretty at second spot with nine points, which includes four wins out of five games with the match against India being washed out.
In reply, Afghanistan couldn't really put on a partnership that took it away from Ireland, who kept picking up important wickets.
