Rosenior was sacked as Brentford manager in November 2006

The 43-year-old former Brentford and Torquay manager won one cap for the Leone Stars as a player in 1994.

The match at Brisbane Road will be their first game on English soil.

The secretary general of the Sierra Leone Football Association (SLFA) Alimu Bah confirmed the move but insisted it was just for the Leyton Orient match.

"Leroy Rosenior will be with Sierra Leone for the game and the team will possibly stay stay in London for a while to train under him as they prepare for the Togo match," Bah told BBC Sport.

However Sierra Leone's preparations for the Leyton Orient game have hit problems after the British High Commission refused visa applications from 15 of the members due to travel to London.

Only two players and one of the 10 officials who applied for visas were issued with the necessary documents to travel.

One of the officials refused a visa is the Leone Stars coach Jebbor Sherrington.

"We applied for seven home-based players to be granted visas - five of which were denied, which is a great pity for those players as I know how much they wanted to play," Sierra Leone FA chief Nahim Khadi said on Wednesday.

"However I want to assure the public that a squad of twenty will be here, 18 of whom are based in the top European leagues and two home-based players."

The SLFA will now have to rely on the foreign-based players that they have invited for the game.

The Leone Stars play Togo in a 2008 African Cup of Nations qualifier on the first weekend in June.

Rosenior was appointed as Brentford boss last summer, but was sacked in November following a disappointing start to their League One season.