The Middlesbrough chairman, Steve Gibson, will target Alan Curbishley as his new manager if Martin O'Neill turns down the job.
In the meantime, the Teesside club have entered talks with Chelsea's Germany international Robert Huth over a £4m transfer this summer.
Curbishley, 49, is on holiday in New Zealand having left Charlton at the end of the season after 15 years in charge. He will be Middlesbrough's third choice after Terry Venables and O'Neill but will be requested to come back to England to discuss personal terms should the former Celtic manager turn down Gibson.
O'Neill is expected to give an answer in the next few days and should he decline, Gibson will have no hesitation in giving the job to Curbishley as he overhauls the club following Steve McClaren's departure to take over the England team after the World Cup finals. Central to O'Neill's consideration in taking the job is his wife Geraldine's treatment for cancer.
Although Curbishley said he wanted to take a break from football this year, after he was one of the candidates for the England job, he is understood to be interested in taking over at the Riverside stadium next season.
Gibson has already shown how determined he is to rebuild Middlesbrough by bidding for Huth, who has been given permission to leave Chelsea by Jose Mourinho. There is also interest in Huth from Everton, who should seal a £8.5m deal for Crystal Palace striker Andy Johnson tomorrow. While the fee they have spent on Johnson is sure to have an impact on the budget for Huth, Everton have been told by Chelsea that they could spread the payments for him over the course of his contract.
Another club looking at Huth is Newcastle. However, talks between Middlesbrough and Huth are understood to be fairly advanced.
The other central defender option for Everton is Joleon Lescott of Wolves. However, the Championship club, whose parachute payments from their Premiership relegation are due to run out this summer, want the fee for the player to be paid in full which could be a problem for Everton.