Wesley spent the most successful part of his career with Romanian club Vaslui between 2009 and 2013, netting 61 times to become the Liga I top foreign goalscorer.
[6] On 14 April, Wesley scored Vaslui's first goal from a scissor-kick following Nemanja Milisavljević's cross, in a cup match against Unirea Urziceni, helping his team to advance in the semi-finals for the first time.
[7] Four days later, during a two-minute stretch in the first half against Politehnica Timișoara, Vaslui came back from a two-goal deficit to win the match with 4–3, with Wesley scoring one of the goals.
[8] On 11 June, he scored Vaslui's winning goal against Universitatea Craiova, helping his team finishing fifth in Liga I and securing its spot for UEFA Europa League, for the second year in a row.
[10] On 30 July 2009, Wesley capped his first appearance in European club competition, playing 90 full minutes, in the 2–0 home win against Omonia Nicosia.
[11] On 6 August, he scored in the second leg against Omonia Nicosia from an 18-yard free kick, qualifying Vaslui in UEFA Europa League's play-off round.
[16] On 3 October, Wesley scored his team's first goal in Marius Lăcătuş's first competitive match as manager, in Vaslui's 3–1 home win over Astra Ploieşti.
[18] On 23 November, he scored Vaslui's second goal against CFR Cluj, helping his team winning its eighth match in a row, in all competitions.
[22] On 15 April, he helped his team to qualify in the Romanian Cup final for the first time, scoring Vaslui's second, in the 4–0 victory against FC Braşov.
[34] On 6 December, Wesley shared with Eric de Oliveira, the Foreign Player of The Year award from FRF at the Romanian Football Ceremony from Bucharest.
[39] On 28 February, Wesley came off the bench at the half-time and scored two goals against FCM Târgu Mureş, maintaining his team in the title chase.
[46] On 15 August, Wesley scored Vaslui's first goal against Concordia Chiajna in a 3–0 victory, which ended a four-game goalless streak for his team.
[47] However, he was substituted in the forty-second minute, due to an injury that forced him to miss the first leg of UEFA Europa League play-off match against Sparta Prague.
[48] He made his come-back in the second leg, leading his team to a historical qualification in the group stages of UEFA Europa League.
[59] On 22 December, Wesley also won Gazeta Sporturilor's Liga I Foreign Footballer of the Year Award, beating his teammate Adaílton.
[61] On 15 March 2012, he helped his team to qualify in the Romanian Cup semi-finals, for the third time in the last four years, scoring twice against Oțelul Galați.