Caddick was born in Christchurch, New Zealand to English parents, and educated at Papanui High School. As a youngster, he modelled his bowling action on that of Richard Hadlee. He appeared three times for New Zealand Young Cricketers, all of his appearances coming in February 1988.

His performances were unremarkable, the highlight being an unbeaten 20 with the bat and bowling figures of 1/16 off three overs in the first One Day International (ODI) against the touring India Under 19 team. In spite of his modest figures in the two matches against the Indians, he retained his place for the first match of the McDonald's Bicentennial Youth World Cup. However, after struggling with 0/39 he lost his place, and did not appear for New Zealand again.

Frustration at what he saw as a lack of opportunities to be selected for the New Zealand Test side drove him to try his luck in England, something New Zealand captain Ken Rutherford would later rue, commenting that "he slipped through the net and given our lack of depth we can ill afford to lose players like him". He played a handful of games for Middlesex Second XI in late 1988 and early 1989, taking 17 wickets in four matches for them at 26.71. On his Somerset Second XI debut in June 1989, Caddick took 8/46 in Surrey Second XI's first innings.

He was restricted to playing in the Second XI Championship for the 1990 and 1991 seasons, as Jimmy Cook was the club's overseas player and Caddick had yet to serve his four years to qualify as an English player. In spite of this, he made his first-class debut for Somerset against the West Indians in May 1991, but his only further match of the season was against the touring Sri Lankans in the August.

His County Championship debut and breakthrough came in the 1992 season, with Caddick immediately amongst the wickets, taking 4/96 against Gloucestershire. Later in the season, he took his maiden 10 wicket haul against Kent, and finished the season with a respectable 71 wickets at 27.01. He impressed the right people and was rewarded with his county cap, and a place in the England A squad touring Australia. He shone on the tour, finishing with a first-class bowling average of 28.60, by far the best on the England team.^[17] A strong start to the following season, including a career best 9/32 in the second innings of a match against Lancashire,^[18] saw him called up to the Test and one-day squads for the 1993 Ashes series.

Period of uncertainty