Sir Trevor Brooking believes the Football Association will find it hard to replace Mark Palios, who quit as chief executive on Sunday.
Palios, who made Brooking director of football development at the FA in 2003, resigned in the wake of allegations about his affair with Faria Alam.
Brooking said: "I was saddened and shocked when I heard he'd resigned.
"He made a big contribution in his short time and it won't be easy finding the right person to succeed him."
Brooking is now being tipped to play a key role in any reorganisation of the Football Association.
Palios has gone and England coach Sven-Goran Eriksson, who also had an affair with FA secretary Alam, faces an inquiry into his involvement.
Eriksson is accused of misleading his bosses over the relationship - which he denies - and allowing them to release an initial denial on his behalf which had to be withdrawn five days later.
Palios was forced to resign after the News of the World revealed the FA offered it full details of the Swede's affair with Alam in exchange for keeping quiet over the chief executive.
Brooking, a former BBC pundit, has been tipped to take over from Palios, or FA chairman Geoff Thompson if he resigns, or even Eriksson as England boss.
But for now the former West Ham midfielder is merely lamenting the loss of his old boss.
"He did some very good work for the FA at a difficult time," Brooking said.
"His particular area of expertise is finance and in that sense he has made an excellent contribution to the FA and will be a tough act to follow.
"I consider him a decent man who brought me into this job and became a good friend."
Palios immediate replacement is David Davies, who is in caretaker charge but who could still come under scrutiny himself from the inquiry.
Brooking is free of any taint of scandal and could be asked to take over the reins from Davies if he is forced out.
Former England international Brooking may even be seen by some as a long-term replacement to restore the FA's battered reputation.
Although he lacks the financial skills of qualified accountant Palios, Brooking does have administrative experience from his time as head of Sport England.