The Citizens enjoy a comfortable lead on top after winning seventeen of the twenty-one matches in the Premier League, losing just one game. They reached this stage after defeating St. Patrick 2-0 and Sliema Wanderers 5-2.
Mosta, on the other hand, beat Msida St. Joseph 1-0 and Xewkija Tigers 3-1. They missed out on a place in the Championship Pool but now aim at securing a place in the semi-finals of the competition for the first time in the history of the club.
Mosta defender Yannick Ossok is suspended.
The two teams met twice this season with Valletta winning 3-0 and 1-0.
Meanwhile in the other quarter-final, Hamrun Spartans are firm favourites to secure a place in the semi-finals as they take on First Division side St. George’s.
After defeating Dingli Swallows 3-1, the Spartans registered one of the biggest surprises as they beat Birkirkara 3-2. In their last league outing, they beat Marsaxlokk 6-2.
The Saints defeated Mtarfa from Division 3, Gharghur from Division 2 and Lija Athletic from Division 1. In Division 1, they lost six out of the last seven matches.
In these matches, extra-time will be played if necessary and if the result is still draw, penalty-kicks shall be taken in accordance with the Laws of the Game.
The semi-finals will be played on May 19 and 20 with the final scheduled for May 27.