Cardiff hunting Springbok
According to the Welsh online newspaper the WalesOnline, the 33-year-old is set to leave Ulster and could be on his way to Arms Park.
The once-capped Springbok has been a big success with Ulster since joining them from Super Rugby side the Lions in 2014, making the Pro12 Dream Team.
The Blues have been in the market for a lock for some time now. They were interested in Welsh internationals Luke Charteris and Bradley Davies, only for them to head for Bath and the Ospreys respectively.
Van der Merwe would bring a real physical presence, while he is renowned for his technical expertise at the lineout, his strong scrummaging and outstanding work-rate.
He is also known as an impressive figure both on and off the field, with his organisational skills and professionalism.
Born in Paarl, in the Western Cape of South Africa, he began his career with the Potchefstroom-based Leopards, before switching to the Golden Lions in Johannesburg.
He stepped up to the Lions Super Rugby franchise in 2007 and made 85 appearances for them over seven years.
After being included in several Springbok squads, he finally made his debut against New Zealand in October 2013, heading for Ulster the following year.
In all, he has made 67 appearances for the Irish province, scoring five tries and being a virtual ever-present. At the end of his first season in Belfast, he was named in the Pro12 Dream Team.
Having arrived from the Lions on an initial two-year deal, he then signed a one-year extension to cover this season.
His move to the Blues would need to receive WRU approval, but if that is granted he would be a quality addition to their second row resources.
walesonline.co.uk