Abdoun arrives from Greek Superleague champions Olympiacos for a fee believed to be in the region of £1.5million, and has signed a three-year contract with the Championship club.

"I am very happy to sign for this historic club and it is a big opportunity for me to prove my ability. Adlene Guedioura told me many great things about this football club so I am delighted to be here," he told the club's official website.

"At Olympiacos I played in the Champions League but Nottingham Forest have already won two European Cups and with the size of the club, we should be playing in the Premier League."

"The objective for this season is to get promotion because the city and the football club should be in the Premier League. That is the aim for the players, the chairman, the manager and the supporters and we will be working really hard to deliver it."

The 27-year-old, who has previously made one appearance in England during a 12-month loan spell with Manchester City, scored 15 goals in 73 outings in Greece.

Meanwhile, Mackie's acquisition from QPR has been confirmed on Twitter by the club's owner Fawaz Al Hasawi, who wrote: "I'm delighted to announce we have signed Jamie Mackie on a three year deal."

The Scotland international striker handed in a transfer request on Thursday and is now set to bring his three-year stay at Loftus Road to an end.