A WICB release on Friday simply stated that Gayle "has been replaced due to injury". Gayle last played an international match in September, and despite being touted for a quick recovery from a lower back injury, he did not feature in even a single game during West Indies' curtailed tour of India in October. He did, however, return to competitive cricket by signing up for Lions in the Ram Slam T20 Challenge, scoring two fifties and a hundred in his first three games.
Smith, whose last appearance for West Indies was back in July 2013, has been in fine form in first-class cricket, having stroked two half-centuries and a hundred in his last three games for Windward Islands in the Regional 4 Day Tournament. He has played 33 Tests for West Indies, but none since May 2011, when he was dropped following two low scores against Pakistan.
The WICB also confirmed that fast bowler Sheldon Cottrell will join the squad on Friday. The selection panel had requested that Cottrell play in the third round of the first-class competition to determine his match readiness after he had sustained an injury during West Indies A's tour of South Africa. Cottrell responded by collecting 5 for 42 for Jamaica against Trinidad and Tobago, helping his team to first-innings points.
West Indies will begin their tour with a three-day game in Benoni on December 10, before starting the first of three Test matches on December 17, in Centurion.