Later in the 1894 season, Barnes was invited to play for Warwickshire, who were due to enter the County Championship in 1895. His debut was in a minor match against Cheshire at Edgbaston on 20–21 August. Barnes bowled only 8 overs, taking none for 27, and the match was drawn. On 23 August, Barnes made his first-class debut for Warwickshire against Gloucestershire at Clifton College Close Ground, except that he did not take the field as play was restricted by bad weather to just 72 overs of his team's first innings, in which they reached 102–2.