[3] Gary Keedy, Lancashire's experienced and established spinner, suffered a broken collar bone in April 2010, immediately before the start of the English cricket season.
With several months on the sidelines, Keedy's absence gave the opportunity to young spinners Kerrigan and Stephen Parry to play first team cricket.
Lancashire coach Peter Moores said "We're lucky in some ways in that we’ve got Stephen Parry, who played quite a lot of first-team cricket last season, but we’ve also got Simon Kerrigan, who bowled beautifully to take six wickets in the pre-season game against Yorkshire in Barbados and we could also use Steven Crofty's off-spin".
[5][6] Kerrigan played 13 first-class matches in his first full season with Lancashire, taking 30 wickets at an average of 32.23 including three five-wicket hauls.
[8] In February 2011, Kerrigan spent 16 days at a spin bowling camp run by the England Cricket Board (ECB).
His aim at the start of the season was to be selected for the England Lions,[11] and following an injury to fellow left-arm spin bowler Danny Briggs this was achieved.
Kerrigan was called up to the Lions squad to face Sri Lanka A in a three match one-day series in August.
[11] In the penultimate County Championship match of the season Kerrigan took career-best innings figures of 9/51 to take Lancashire to a 222-run win over Hampshire.
The final wicket of the match was claimed with just four minutes of play left and was greeted with a mini pitch invasion as the victory kept Lancashire in contention for the title.
[14][15] Kerrigan contributed 24 wickets from the four Championship matches he played that season, placing him sixth on Lancashire's list of leading wicket-takers for the competition.
[21] In the year Lancashire began their title defence, Kerrigan succeeded Keedy as the club's first-choice spinner in the County Championship.
[33] Graeme Swann retired from international cricket during the series, and Kerrigan's "traumatic debut" meant that it was unclear who would replace him in the Test team.