One of New Zealand's elite rowing crews faces serious disruption to their preparation for the European summer tour.

The women's pair world champions Nicky Coles and Juliette Haigh have been off the water as a duo for a fortnight because of a rib injury to Haigh.

She is expected to begin light rowing again this weekend.

Coles has been rowing in the singles and filling in for the women's eight.

Unfortunately there is no guarantee the injury will be be totally right because it is aggravated by over use.

Tonks wants his crews to feel the intensity of genuine competition again as soon as possible.

The elite crews will pit themselves against each other in staggered start races over the next three days to simulate World Cup conditions, with Tonks saying they will race in World Cup conditions over the weekend, as well as being against world record times.

He says you can do as much training as you like but there is nothing like racing in real competition as the rowers build towards the European summer season and August's world championships.

The crews will leave in around nine weeks.