Cregan first came to prominence on the inter-county scene as a dual player with the Limerick minor hurling and football teams in the early 1960s.
That year Cregan's side reached the 'home' final of the National Hurling League with Cork providing the opposition.
Tipp ploughed on in the second-half; however, Cregan scored two decisive goals to put Limerick in the lead.
Richie Bennis scored the winning point in spite of some reports that it trailed wide as it went over the bar.
Limerick were far from impressive when they defeated London in the next game, setting up an All-Ireland final meeting with the reigning champions Kilkenny.
Cregan was switched from his usual forward position to centre-back where he marked Kilkenny's scorer in chief Pat Delaney.
This victory allowed Cregan's side to advance directly to the All-Ireland final where Kilkenny provided the opposition once again.
In spite of this Limerick stormed into an early lead, however, this was diminished as Pat Delaney, Eddie Keher and Mick Brennan scored goals.
Cregan's side contested the Munster finals of 1975 and 1976, however, Cork were victorious on both occasions as Limerick went into decline.
They were completely trounced again in 1979 on a score line of 2–14 to 0–9 as Cork captured a record-equaling fifth Munster title in-a-row.
After an exciting seventy minutes Cork's hopes were dashed by 2–14 to 2–10 as Cregan collected a third Munster medal.
At the 1981 general election, Cregan was an unsuccessful Fianna Fáil candidate in the Limerick East constituency.
Cregan, however, continued playing for his county for another few seasons, however, Cork returned as the dominant force in Munster.
He first played for his province in 1968 as Munster defeated Leinster giving Cregan his first Railway Cup medal.
At the time Offaly were an up-and-coming hurling team in the championship, however, it would be 1994 before Cregan's charges first tasted success.
Limerick lost possession after the puck-out and Offaly rampaged up the field for another goal courtesy of Pat O'Connor.
Cregan's side defeated Down in the penultimate game of the championship, setting up an All-Ireland final meeting with Clare.
Éamonn Taaffe, who entered the game unnoticed as a substitute, score a decisive goal for Clare with four minutes left on the clock.
Johnny Dooley levelled for Offaly, however, Anthony Daly and Jamesie O'Connor scored the final points for Clare giving them a 1–13 to 2–8 victory.
In spite of the successes in the early 1980s Limerick failed to even reach a Munster final during his first term in charge.
At the time Limerick had enjoyed two recent Munster Championship victories, however, they had failed to win an All-Ireland title.
Cregan's magic touch failed to work in Limerick, however, his side did contest the Munster final in 2001.
After a poor performance in the Munster Championship, he tendered his resignation, citing disagreements between himself and the Limerick county board over dual players.
[4] He finally resigned in June 2002, after Limerick's poor performance in the qualifiers saw them defeated by Cork in the first round.