In 1916, before his father imposed a ban on competitive cricket, Constantine had played briefly for Shannon Cricket Club; he returned to the club in 1920.
Initially, he appeared in the second team, but after scoring 50 runs in an hour during his third game, was promoted to the first eleven.
Cricket in Trinidad at the time was divided along racial lines; Shannon was mainly for black lower middle-class players such as teachers or clerks.
The club was competitive and highly motivated, partly as a reaction to the racial discrimination that its players and supporters encountered in their daily lives.
Constantine's cricket thrived in this atmosphere, and the club helped to form some of his political views.
He particularly noticed that in Trinidadian and West Indian cricket, white and light-skinned players were often favoured over black players of greater ability.

Constantine's reputation continued to grow.
An innings for Shannon in 1921 against renowned fast bowler George John received great local publicity, but according to the cricket writer and social historian C. L. R. James, this was the only time prior to 1928 that Constantine played in such an effective way.
Constantine's father, still a formidable player, did not put himself forward for selection into the Trinidad team in 1921, in the hope that his son would replace him.
The white captain of the Trinidad team, Major Bertie Harragin, recognised the younger Constantine's promise, and selected him to play in Trinidad's Inter-Colonial Tournament match against British Guiana.
Unfortunately, Constantine arrived late after a newspaper advertised the wrong starting time, and did not play.
However, he made his first-class debut in the following match, the final of the tournament, against Barbados on 21 September 1921.
He scored a duck in his first innings, batting at number eight in the batting order.
After taking two wickets at a cost of 44 runs in Barbados' only innings, he scored 24 in his second innings, batting at number three.

Constantine played for Trinidad in the next Inter-Colonial Tournament, in British Guiana in 1922.
Although in two games he scored only 45 runs and took four wickets, commentators considered his fielding in the covers to be exceptional, and he retained his place in the team largely as a fielder.
Although Trinidad lost to Barbados in the final, the Barbados captain Harold Austin, who was also captain of the West Indies team, was impressed by Constantine.
Mainly on the strength of his fielding, Austin secured Constantine's selection for the 1923 West Indian tour of England; it was a surprising choice, as there were other candidates who appeared to have stronger claims.
By this time Constantine was working for Llewellyn Roberts, a larger solicitors' practice which paid better.
As his new employer's longer working hours restricted Constantine's cricket practice, when he was selected for the West Indies tour he resigned his position.
In 1916, before his father imposed a ban on competitive cricket, Constantine had played briefly for Shannon Cricket Club; he returned to the club in 1920. Initially, he appeared in the second team, but after scoring 50 runs in an hour during his third game, was promoted to the first eleven. Cricket in Trinidad at the time was divided along racial lines; Shannon was mainly for black lower middle-class players such as teachers or clerks. The club was competitive and highly motivated, partly as a reaction to the racial discrimination that its players and supporters encountered in their daily lives. Constantine's cricket thrived in this atmosphere, and the club helped to form some of his political views. He particularly noticed that in Trinidadian and West Indian cricket, white and light-skinned players were often favoured over black players of greater ability.
Constantine's reputation continued to grow. An innings for Shannon in 1921 against renowned fast bowler George John received great local publicity, but according to the cricket writer and social historian C. L. R. James, this was the only time prior to 1928 that Constantine played in such an effective way. Constantine's father, still a formidable player, did not put himself forward for selection into the Trinidad team in 1921, in the hope that his son would replace him. The white captain of the Trinidad team, Major Bertie Harragin, recognised the younger Constantine's promise, and selected him to play in Trinidad's Inter-Colonial Tournament match against British Guiana. Unfortunately, Constantine arrived late after a newspaper advertised the wrong starting time, and did not play. However, he made his first-class debut in the following match, the final of the tournament, against Barbados on 21 September 1921. He scored a duck in his first innings, batting at number eight in the batting order. After taking two wickets at a cost of 44 runs in Barbados' only innings, he scored 24 in his second innings, batting at number three.
Constantine played for Trinidad in the next Inter-Colonial Tournament, in British Guiana in 1922. Although in two games he scored only 45 runs and took four wickets, commentators considered his fielding in the covers to be exceptional, and he retained his place in the team largely as a fielder. Although Trinidad lost to Barbados in the final, the Barbados captain Harold Austin, who was also captain of the West Indies team, was impressed by Constantine. Mainly on the strength of his fielding, Austin secured Constantine's selection for the 1923 West Indian tour of England; it was a surprising choice, as there were other candidates who appeared to have stronger claims. By this time Constantine was working for Llewellyn Roberts, a larger solicitors' practice which paid better. As his new employer's longer working hours restricted Constantine's cricket practice, when he was selected for the West Indies tour he resigned his position.
Learie Constantine