Xavier played for clubs in Portugal, Italy, Spain, the Netherlands, England, Turkey and Germany before retiring with the LA Galaxy of Major League Soccer (MLS) in 2008.

From his debut in 1993, Xavier played 20 games for the Portugal national team, and was selected in their squads for UEFA Euro 2000 and 2002 FIFA World Cup.

This stint with the Italian club started a series of transfers across Europe: in 1996, Xavier was sent to Real Oviedo, then after two seasons he moved to PSV.

At the start of the 2005–06 season, Xavier was without a club but at the end of August, he signed for Middlesbrough to replace Michael Reiziger after the Dutchman was sold to PSV.

[8] Following the UEFA Cup tie against Skoda Xanthi on 29 September, Xavier was administered a drugs test and failed.

Xavier remained employed by the club and unsuccessfully appealed the decision; in January 2006 he said that he would take UEFA to the Court of Arbitration for Sport.

He played in his first game with the Galaxy on 17 June 2007 at home against Real Salt Lake, setting up fellow new signing Edson Buddle in a 3–2 win.

Xavier's full international debut for senior team came on 31 March 1993, away in Switzerland in qualification for the 1994 FIFA World Cup.

Xavier was initially given a nine-month ban from football for his vociferous protests against referee Günter Benkö's decision to award the penalty,[22] but it was eventually reduced to six months.

In July 2013, Xavier signed to be manager of Portuguese top division club Olhanense for the upcoming 2013–14 Primeira Liga season.

[27] In July 2015, Xavier signed a one-year deal with another team in the second division, Desportivo das Aves.

[31] After conceding an added-time goal to Guinea, the Black Mambas missed out on the tournament in Egypt but he was assured of a new deal by the Mozambican Football Federation; this offer was rescinded after a poor performance at the 2019 COSAFA Cup in South Africa.