A former reserve-team captain, Kewley faced formidable competition for a regular place in a Liverpool side enjoying one of the most successful periods in the club’s history. Two successive summer loans to Dallas Tornado opened up a different route for his career. In July 1977, Liverpool accepted a £10,000 offer from the American club, where Kewley had been playing alongside fellow Liverpool reserve Max Thompson. Dallas also wanted Thompson, but Liverpool rejected their approach for the centre-back. Bob Paisley explained that the loans had been arranged to help the players’ development rather than prepare them for sale, and left Kewley to decide whether to make the move permanent. “Now it is up to them to speak to the lad. It is for him to decide,” he told the Liverpool Daily Post.
Kewley initially returned to Anfield and continued to press his claims in the reserves. By October 1977, the Daily Post reported that he had become sharper and was showing a greater threat in front of goal from midfield. Kewley spent six years at Liverpool but made just one competitive first-team appearance, coming on as a substitute against Middlesbrough at Anfield in a 2–0 First Division victory over Middlesbrough on 2 January 1978. He replaced Terry McDermott after just ten minutes with the match still goalless, giving him around 80 minutes of first-team football in front of 49,305 spectators. David Johnson opened the scoring in the 39th minute from Steve Heighway’s assist, before Heighway secured the victory ten minutes from time.
On 27 February 1978, the Liverpool Echo reported that the 22-year-old had finally signed for Dallas in a £10,000 deal. The newspaper also noted that he had earned a player-of-the-year award during the previous summer’s spell there. Kewley played for Tornado until 1979 before moving into the Major Indoor Soccer League with Wichita Wings, where he remained until 1989. He subsequently made Wichita, Kansas, his home and continued his involvement in football through college coaching.