Floriana Claude began his career playing for his local side
Floriana during the
1996–97 season. Mattocks went on to make three appearances that season, scoring his first goal for the club, as
Floriana finished in 3rd position in the
Maltese Premier League. Claude started to force his way into the first team at
Floriana with some impressive displays during the
1997–98 season, as
Floriana finished in 5th position, with Mattocks making 14 appearances, but failing to score any goals. For the
1998–99 season, Claude's first team opportunities were restricted to just 10 appearances, he did however score one goal, which helped
Floriana record another 5th-place finish in the
Maltese Premier League. During the
1999–00, Mattocks firmly established himself in the
Floriana first team squad, making 22 appearances and scoring three goals, as
Floriana finished in an impressive 4th position in the
Maltese Premier League. Mattocks went into the
2000–01 season hopeful of improving on the club's previous finish, however
Floriana managed another 5th-place finish in the
Maltese Premier League, with Claude making 25 appearances, and scoring four goals. Claude continued to impress and went into the
2001–02 season hoping to help
Floriana finish in a higher league position, but again they finished in 5th position in the
Maltese Premier League, as Mattocks made 25 appearances, but failed to score any goals. For the
2002–03 season, Claude and
Floriana almost took an almighty fall from grace, as they finished the season in the relegation pool, and narrowly avoided relegation after finishing in 8th position, with Mattocks making 20 appearances, and scoring five goals to help the team cause. Despite the poor form of
Floriana, Mattocks did receive his first cap for the
Maltese national team. Claude went into the
2003–04 season in great form, and attracting interest from other teams in the
Maltese Premier League, Mattocks completed the season with
Floriana, helping the club return to the championship pool to record a 6th-place finish. Claude made 22 appearances, scoring two goals during the season.
Sliema Wanderers Following a host of impressive performances for
Floriana, Claude joined fellow
Maltese Premier League side
Sliema Wanderers for the
2004–05 season. The move was an instant success as Mattocks helped his new club to the
Maltese Premier League title. During the season Claude made 23 appearances and scored three goals. For the
2005–06 season, Claude began the season with
Sliema Wanderers making 9 appearances, but scoring no goals. During the January transfer window of 2007, Claude switched to
Valletta on loan for the remainder of the season. During the season with
Valletta, Mattocks made 12 appearances and scored three goals to help the club to a 5th-place finish in the
Maltese Premier League, with his contracted club
Sliema Wanderers finishing in 2nd position. Claude returned to
Sliema Wanderers for the
2006–07 season, he made 13 appearances, but failed to score any goals throughout the season, as
Sliema Wanderers finished in 2nd position in the
Maltese Premier League for the second consecutive season. Mattocks began the
2007–08 season with
Sliema Wanderers. Claude made only one appearance, without scoring, and left the club during the January transfer window of 2008.
Sliema Wanderers did go on to finish in 4th position in the
Maltese Premier League that season.
Valletta Claude rejoined
Valletta for the second half of the
2007–08 season, he went on to make 12 appearances and scored one goal, as Mattocks won the
Maltese Premier League title for the second time in his career, as
Valletta finished in 1st position.
Marsaxlokk On 20 August 2008, it was confirmed that Claude Mattocks had joined
Marsaxlokk from
Valletta, teaming up with former Valletta team-mate
Saviour Darmanin, who had made the same move the previous month. Mattocks was allocated with the number 21 shirt. Mattocks made his debut for
Marsaxlokk four days later on 24 August 2008, where the side played newly promoted
Qormi. He came off the bench as a second-half substitute for
Christian Cassar on the 56th minute, and it was Mattocks, with the game three minutes into stoppage time, who crossed a ball into the box, to be met by
Julio Alcorsé, who flicked the ball past a helpless
Matthew Farrugia to secure a 1–1 draw. ==Honours==