Wolves know they missed out on millions by not including a sell-on clause in their original sale of Tottenham star Robbie Keane.

Having progressed through the old gold and black ranks, Keane headed to Coventry in a £6 million move that was then a British record for a teenager.

However, Wolves opted against incorporating a sell-on clause so when the hot-shot later moved to Inter Milan for big bucks, his first club failed to take a slice.

Ex-Wolves managing director John Richards told the Sunday Mercury: "The decision was taken to have the money in the bank today, rather than hope for money that may or may not come tomorrow.

"We needed to strengthen the team but there wasn't any money available to buy players without selling first. The more money we could generate for the manager, the more team strengthening he could do immediately.

"Only two clubs put in bids in the region of what we were looking for - one was £5.5 million with the possibility of a sell-on fee, generally 10 per cent, and the other was from Coventry, who offered the straight £6 million.

"Bear in mind that any sell-on fee only relates to the difference in the buying and selling prices. Therefore, when Robbie did move from Coventry for £11 million, the lower offer with the sell-on clause would only have generated Wolves an additional £0.55 million, just £50,000 more than we got anyway.

"Of course, there are other unknowns, such as the other club never selling, in which case Wolves would have received nothing, or Robbie getting a serious injury.

"To be honest, it wasn't a difficult decision to make."