After a series of outstanding displays, he was signed by Portsmouth F.C. for a transfer fee of £8,000 in October 1968. Hand would impress enough at Portsmouth to earn a call up to the Republic of Ireland national football team and went on to earn 19 caps for his country. He stayed with Portsmouth until being released at the end of the 1975/76 season. After a brief spell in South Africa, Hand was persuaded back into football by Shamrock Rovers but after only nine games, returned to Portsmouth FC. He left again in 1979, after playing a total of 277 times in the league for them.
In Hand's first World Cup qualifying campaign, Ireland narrowly lost out to France on goal difference. Ireland conceded a late goal to Belgium after having what most commentators describe as a 'perfectly good goal' disallowed. The image of Hand on the bench with his head in his hands post match is widely shown in Ireland as one of Irish sport's most heartbreaking images.
Ireland finished an unremarkable 3rd in the qualifying campaign for Euro 84 and shortly after Hand agained combined club and international management when he was appointed manager of St Patrick's Athletic FC, however he lasted only one season with the Dublin club. After failure to qualify for the 1986 World Cup Hand was sacked by the FAI and replaced by Jack Charlton.
In 1988, Hand was appointed manager of Huddersfield Town and remained there until 1992. Hand also briefly managed Shelbourne during the 1993-94 season.