[3] Brennan played two second XI matches in 1946, but first team opportunities were blocked by Paul Gibb, Arthur Wood and Kenneth Fiddling.
However, all three had left the club by the start of the 1947 season, leaving Brennan and Harry Crick in competition for the keeper spot.
[6] He was also a regular in both the 1949 and 1950 seasons, despite Jack Firth, Yorkshire's second choice keeper, averaging more with the bat in his limited opportunities.
[8] The improvement came at the right time as he was selected by England, to replace Godfrey Evans, for the fourth Test with South Africa.
[11] He was chosen for the MCC's tour of India and Pakistan that winter, however Dick Spooner was selected as keeper for all five Tests.