The 2016 ISL runners-up were a bit short-handed in the goalkeeping department, having signed only one frontline goalkeeper in Subhasish Roy Chowdhury so far.
The recruitment of Rachubka, who started his professional career with Manchester United, should go a long way in easing the nerves of head coach Rene Meulensteen as he prepares for his first stint in India.
The 36-year-old custodian, born in the USA, moved to England when he was seven years old and possesses dual nationality. Though he has represented England at the youth levels, he did not make the cut for the senior team.
Rachubka made his debut for Manchester United in the 2000 FIFA Club World Cup and made his league debut against Leicester City in the 2000-01 season. However, he moved to Charlton Athletic soon before spending time at a host of clubs including Huddersfield Town, Blackpool and Leeds United.
His most recent spell was with FC Bury in the League One, the third tier league in England.
The Tuskers have already signed four overseas players in Wes Brown, Courage Pekuson, Nemanja Lakic-Pesic and Iain Hume. Rachubka becomes their fifth signing, which leaves them spots for two more foreign players plus a marquee signing.