Shortly thereafter, Butler made his debut during Sunderland's 3–2 win over Walsall during the 1999/2000 season after coming on as a substitute. Butler was on the verge of breaking into the first team and was successful for the reserves. This earned him a chance to make his first league appearance after once again coming on as a substitute against West Ham. He would soon earn praise, being considered by some as the Irish version of Joe Cole.
