Career
He played primarily in the fullback position. Sigsworth made his first grade debut for Newtown Jets in 1977, enjoying a stellar season in 1981 when he made his Test and State of Origin debut while helping take the Jets to the grand final, which they lost 20–11 to Parramatta. He was selected for the New South Wales Blues for three State of Origin games from 1981 to 1983 and two Tests with the Australian Kangaroos in 1981, he also played in two Interstate Series games that year as well.
After two seasons with the Sea Eagles he joined the then-premiers Canterbury-Bankstown Bulldogs in 1985.
His time at Belmore is remembered for his send-off in the 1986 grand final for a high tackle on Brett Kenny. He is the last player to have been sent off in a rugby league grand final.
The Bulldogs suffered a 4–2 defeat by the Eels. Sigsworth spent one season with Balmain Tigers in 1987 before drawing the curtain on his Sydney first-grade career because of an in-operable knee injury.
Sigsworth then moved into coaching, in 1996 he joined English club Hull and coached the team to their first First Division championship title in 1997.
Sigsworth parted ways with the club in mid-1999 and returned to Australia where he linked up again with the Balmain Tigers as assistant coach to Wayne Pearce. The club merged with Western Suburbs and after one season in 2000 at Wests Tigers, Pearce stepped down as coach and Sigsworth also left. Sigsworth has not been involved with an NRL club since.
Sigsworth remains involved in rugby league as the chairman of the New South Wales Origin Legends who support various charities with their regular events such as re-unions, luncheons, golf days.
In 2008, the centenary year of rugby league in Australia, Sigsworth was named in the Newtown Jets 18-man team of the century.