The 29-year-old has enjoyed his first week of training with the Region following his exploits with Western Province.
Kingsley Jones commented: “"The sooner we introduce Brok the better. He is keen as mustard and is knocking on the door and wants to play.
"Brok has fitted in straight away and having another South African here in Rynard has helped him."
The Men of Gwent have also welcomed back Ross Wardle, Cory Hill, Andrew Coombs and Joe Davies who have all been included in the match day squad after fully recovering from their injuries.
Geraint Rhys Jones will start at full-back for the Dragons and will be joined in the back three alongside teenager Ashton Hewitt and Aled Brew. The centre paring takes on the form of Matthew Pewtner and Ross Wardle, who has returned from a long term knee injury. Dorian Jones gets the nod to start as fly-half whilst 22-year-old Jonathan Evans takes on the scrum-half position.
The front row consists of props Owen Evans and debutant Brok Harris, whilst Elliot Dee takes on the position of hooker. James Thomas, who put on an impressive display against Ulster, retains his place in the second row alongside Cory Hill who returns from injury to captain the side. The back row sees the return of Andrew Coombs at blind side flanker – he will play alongside James Benjamin and Andy Powell.
The replacement bench is made up of: Hugh Gustafson, Phil Price, David Young, Joe Davies, Ollie Griffiths, Luc Jones, Barney Nightingale and Rhys Williams.
Dragons Team to face Harlequins
Geraint Rhys Jones, Ashton Hewitt, Matthew Pewtner, Ross Wardle, Aled Brew, Dorian Jones, Jonathan Evans; Owen Evans, Elliot Dee, Brok Harris, James Thomas, Cory Hill (c), Andrew Coombs, James Benjamin, Andy Powell.
Replacements: Hugh Gustafson, Phil Price, David Young, Joe Davies, Ollie Griffiths, Luc Jones, Barney Nightingale, Rhys Williams.
