Arnesen, who brought Lennon to Spurs, left for Chelsea before he could work with his signing but is still proud of the transfer.
"We paid about £500,000 for Aaron and he and Tom Huddlestone cost a combined £1.1million initially," said the Hamburg sporting director. "To sign him for that amount was a no-brainer. In January 2006, Arsenal did a £12m deal for Theo Walcott but we'd taken Aaron for much less. I saw him for Leeds at Watford and he didn't play his best but I could see the material - the pace, the dribble, the cross.