In his second season with Cardiff, Watson made a further 45 appearances in all competitions, including playing in all seven matches of their successful FA Cup run. Ahead of the final, Watson was described as "one of the best tacklers playing this season" in the "Daily Herald". The newspaper also noted that his partnership with Nelson formed one of the "best pairs of backs in the country." Cardiff defeated Arsenal 1–0 to become the only team from outside England to win the competition. He remained prominent during the first half of the 1927–28 season, missing only 2 of the first 20 league matches of the campaign. However, from late December, his season was blighted by injuries; he made only two appearances in the second half of the campaign, the second in a heavy 7–1 defeat against Derby County on 31 March 1928. He underwent knee surgery in October 1928 in attempt to rectify his cartilage injury problems, having not made an appearance during the new season. As such, he appeared only once during the 1928–29 campaign, returning in a 3–1 defeat to Manchester City in the final month of the campaign.