At the start of the 2003–04 season, Arca missed the first three matches, due to being linked a move from the club and expected to leave Sunderland. His first appearance of the season came on 23 August 2003 against Preston North End, starting the whole game in the left–back position, in a 2–0 win. Having regained his first team place, playing in the left–back position, he kept two clean sheets in the next two matches, including scoring his first goal of the season, in a 4–0 win over Bradford City. Since returning to the first team, Arca regained his first team place, playing in the left–back position. His performance was praised by Manager Mick McCarthy and Gary Breen for making a huge difference in recent matches. His second goal of the season came on 27 September 2003, in a 2–0 win over Reading. A week later on 4 October 2003, however, he was sent–off for the second bookable offence, in a 1–0 win over Sheffield United. Arca was sent–off for a second bookable offence once again two months later on 2 December 2003, in a 1–1 draw against Wigan Athletic, resulting a two match ban. After returning to the first team, he scored three goals throughout January. In the January transfer window, Arca was linked a move away from Sunderland; which Manager McCarthy said he's not for sale. But Arca insisted on staying at the club. Following this, he then scored his fourth goal of the season, in a 3–1 win over Walsall on 3 March 2004. However, Arca missed five matches, due to a knee injury he sustained in a 1–0 win over Sheffield United in a FA Cup match. It wasn't until on 27 March 2004 when he made his return to the starting line-up, in a 2–1 win over Derby County. Having regained his first team place for the next five matches, he suffered a knee injury that saw him sidelined for the rest of the 2003–04 season. At the end of the 2003–04 season, Arca went on to make thirty–seven appearances and scoring six times in all competitions. For his performance, he was named PFA Team of the Year for the First Division for the 2003–04 season.