 Just before relegation was confirmed, Docherty was sacked and replaced by ex-Middlesbrough manager Bruce Rioch. Striker Teddy Sheringham, who later played for England and was the highest-scoring player throughout the Football League in the 1990 – 91 season, was sold to Nottingham Forest for £ 2 million after Millwall's 6 – 2 defeat to Brighton & Hove Albion in the Second Division play-offs. Rioch left Millwall in 1992 to be succeeded by Irish defender Mick McCarthy. McCarthy guided Millwall to third place in the new Division One at the end of the 1993 – 94 season. This was their first season at a new ground, at first known as The New Den (to distinguish it from its predecessor) but now called simply The Den, which was opened by the Labour party leader John Smith on 4 August 1993. The new ground was the first all-seater stadium to be built in England after the Taylor report on the Hillsborough disaster. The Lions knocked Arsenal out of the 1994 – 95 FA Cup in a third-round replay, beating them 2 – 0 at Highbury. They also reached the quarter-finals of the League Cup in 1995. Millwall lost 5 – 1 on aggregate to Derby County in the play-off semi-finals that same 1994 – 95 season, in a tie blighted by crowd trouble. McCarthy resigned to take charge of the Republic of Ireland national team on 5 February 1996, shortly after Millwall had been knocked off the top of the Division One table by Sunderland, following a 6 – 0 defeat.
