•His first senior club was
Shamrock Rovers whom he joined in 1980. He went on to spend 3 years at Milltown, making 4 appearances in Europe and scoring one goal .
•Beglin was the last signing made by legendary
Liverpool manager Bob Paisley when he joined from Shamrock for just £20,000 in May 1983. He was gradually introduced to the first team picture over the next 18 months by Joe Fagan, before being given regular games in the left back slot by Kenny Dalglish as a replacement for Alan Kennedy. He made his debut in the left sided midfield position on 10 November 1984 in the 1-1 league draw with Southampton at Anfield. He scored his first goal for the club 5 months later on 10 April 1985 in the 4-0 European Cup Semi-final 1st leg victory over Greek side Panathinaikos at Anfield. Beglin's 85th minute strike put the tie out of reach for the Greek club. Liverpool won the second leg 1-0 to set up a showdown in the final with Italian giants Juventus at the Heysel Stadium in Belgium. Unfortunately, hooligans rioted before the beginning of the game causing a retaining wall to collapse which killed 39, mainly, Juventus supporters, in what came to be known as the Heysel Stadium Disaster.
•In his first season, he established himself as a competent and confident, forward-thinking full back. Liverpool won the
League championship and FA Cup, pipping Merseyside rivals Everton to both, with Beglin picking up medals for each. He also began playing for the Republic of Ireland, picking up the first of 15 caps.
•Then it all went horribly wrong for Beglin. In a
derby League Cup tie against Everton in early 1987, he went into a fairly straightforward 50-50 tackle with full back Gary Stevens and suffered a horrific leg break. The injury was extremely serious and one of the worst leg breaks seen in the professional game. At the time, Liverpool's Alan Hansen described the tackle as "a foot high and an hour late".
•Liverpool reached the final of that competition - they lost 2-1 to
Arsenal - but Beglin could do no more than watch as he tried to recuperate from the injury. Dalglish had reshuffled his defence to cater for his absence, moving Steve Nicol across to the left flank and introducing new signing Barry Venison. As Beglin hoped to make progress the next season, local lad Gary Ablett came through the ranks to take the left back slot. Beglin tried to make a comeback in the Liverpool reserve team but only succeeded in damaging cartilage in his knee. His days at Anfield were over.