"It would have been a good signing for us, but we are over our cap and we accept that we cannot do it," said Van de Velde, who is a strong advocate of the salary cap and of a players' draft to go with it.
Wigan, St Helens and London are arguing that they should have more leeway - the first two because of the extra expense of retaining players in the face of Australian raids three years ago and London because they have no reservoir of ready-made players on their doorstep.
"But they knew that the rule was 50 per cent and they should stick to it," said Van de Velde. "Otherwise, the game is heading for ruin."
The Rugby League Council will consider Super League's pleas for flexibility at its meeting on Wednesday.
Tulsen Tollett will not only be in London's team to play Wigan on Sunday, he is likely to return to his former club from Harlequins for the whole season. As London are already over their limit, however, a long-term deal could raise problems.
Leeds' prop Barrie McDermott will miss the start of the Super League season after being suspended for one match for a spear tackle and four for fighting, both in the "friendly" at York last week.
In Super League's games around Britain in July the match between London and Bradford is likely to be staged at Hibernians' Easter Road ground in Edinburgh after the breakdown of negotiations with Watford.Reuse content