It dates back to 2002 when a then-15-year old Rooney was signed from Pro-Form Sports Management by Proactive Sports Management, which later became part of Formation Group.
The deal resulted in the Football Association fining Mr Stretford £300,000 and banning him from acting as an agent for nine months from July 2008.
The fine and Mr Stretford's £1.3m legal costs were met by Formation Group. However, following Mr Stretford's departure last October to form Triple S Sports and Entertainment Group, which acts for Mr Rooney and his wife Coleen, Formation has begun a legal action to recover the money.
Two weeks ago Mr Stretford, who is defending and counter-claiming in the main proceedings, brought an additional claim for an indemnity against Mr Rodford, alleging breach of fiduciary duties while Mr Rodford worked with Mr Stretford at Proactive.
In documents served by Mr Stretford's solicitors, he described how he saw Rooney as a "prospect" in January 2003, three months after the footballer had turned professional with Everton at the age of 17 and had become the youngest goalscorer in Premier League history.
"It is admitted that by January 2003 Wayne Rooney was an outstanding prospect. He was, however, merely a prospect. The defendant [Mr Stretford] already acted as an agent for numerous highly successful established players," the documents state. "It is denied that the defendant knew that Wayne Rooney was of great importance to the claimants and his own career. The defendant was a successful football agent. His career did not depend on his continuing to act for Wayne Rooney."
"Whilst the defendant was concerned to ensure he acted in the best interests of Wayne Rooney, in this respect he was no different from any other of the numerous footballers for whom he acted."
Formation said it stood by Mr Rodford. "Formation is in litigation with Paul Stretford. Stretford, in his defence, has attempted to rope in our chief executive. The company will continue to defend its position and Neil's position," communications director Mike Wallwork said.