He made 12 appearances for
New South Wales in
State of Origin games between 1989 and 1994 at lock forward. During his State of Origin career, Brad scored 2 tries for a total of 8 points. He was well regarded as a Clyde was recalled to the New South Wales team for the 1999 series but a horse-riding accident in a team bonding exercise before the series opener ruled him out for eight weeks with a damaged shoulder. He represented
the Kangaroos in 19 Tests over five years scoring six tries. He was named Man-of-the Series in 1989 with his
debut tour v New Zealand. Injury in 1990 would prevent him from playing in the mid-season test against
France in
Parkes, however, his
anterior cruciate ligament (ACL) knee injury suffered in Round 20 of the NSWRL season would prevent his selection for the one off Test against New Zealand at the
Athletic Park stadium in
Wellington (played only a week after his knee injury), as well as the
1990 Kangaroo tour. Clyde returned to the Australian team for the
1991 Trans-Tasman Test series against New Zealand where he was one of Australia's best in the 2–1 series win. After starring in the 1991 Grand Final loss, Clyde was named as vice-captain of the Australian team for the tour of Papua New Guinea at the end of the year and was named Man of the Series also. During the
1992 Great Britain Lions tour of Australia and New Zealand, he helped Australia retain
The Ashes, and was awarded the
Harry Sunderland Medal for the Player of the Series. He was also selected to play at lock for Australia in the
1992 Rugby League World Cup final at
London's
Wembley Stadium following the
1992 NSWRL season. Although Australia retained its World Champions crown with a 10–6 win over
Great Britain, Clyde had an unhappy game after dislocating his shoulder midway through the second half. ==Post-playing==