In 1997 Mancini started a new cycle embracing president Cragnotti's project and moving to Lazio. In Rome, Roberto got a lot of satisfaction as he won his second Scudetto in the 1999/2000 season, his second UEFA Cup Winners' Cup and a UEFA Super Cup in 1999, the Coppa Italia twice in 1997 and 1998 and a Supercoppa Italiana.
Already player-coach, he officially became Sven-Göran Eriksson's assistant coach in March 2000, although he kept playing.
He scored 24 goals in 112 appearances for the Biancocelesti (87 the in Serie A, two in the Coppa Italia, nine in the Champions League, six in the UEFA Cup) before moving to England for a brief spell at Leicester City in January 2001.
