Tottenham Hotspur reached an agreement with newly promoted, Watford for the transfer of French midfielder Moussa Sissoko on a two-year contract on Friday.
The France international will be available for Sunday's match against the Spurs, Watford said in a statement.
The financial details of the transfer were not disclosed, but British media reported that the fee was in the region of £5 million.
Sissoko, 32, joined Tottenham from Newcastle United in 2016 and has made 202 appearances for Spurs across all competitions.
He played 44 times in the 2018-19 season, helping Tottenham reach the UEFA Champions League final where they lost to Liverpool.
Tottenham have won their first two Premier League games of the season while Watford have one win and lost one so far.