 By the end of the 1977–78 season, Gilchrist had been joined at Portsmouth by his fellow ex-Saint, Bobby Stokes and St. John had been replaced as manager by Jimmy Dickinson, but he could not prevent Portsmouth being relegated into Division 4.By then, Gilchrist had played his last league game for the club.He made his final appearance for Portsmouth in a Football League Cup defeat at Swindon in August 1978, when he scored one of Portsmouth's goals.