Mr Roberts, born in Bradford but now living in Texas, used to visit the club when he was a boy and was seven when his father died at a school sports day at the Horsfall Stadium.
The club said bringing in good new players was a possibility and that “relegation is not an option.”
Mr Roberts said the mission was to “bring success” and ensure the club had a strong future.
“In the short term, our priority’s to make sure we continue to play in this league and we’ll do that by making sure we have a strong team and a good pitch.
“We don’t know yet whether Horsfall can be our long-term home but we’re talking to the council, who own the site, to see what we can work out.
“If not, we are prepared to relocate and build on another site and we’ll explore all the options.
“We’re ambitious for the future but the new directors can’t go it alone. We’re prepared to invest hard work and money but we need the ongoing commitment of the supporters, players, staff/volunteers, sponsors and partners who have got us this far.
“We know we need to build some strong working relationships with civic and business partners too so that we can secure a long-term win-win situation for Avenue and for Bradford generally.”
New director Joe Mosley, who lives in Leeds, will take charge on a day-to-day basis.
The third new director is Paul Wood, who lives in Harrogate.
A club spokesman said the directors planned to spend money improving the football team.
It has yet to be decided whether to spend money improving the pitch.
Moving to a different site may also be considered, although returning to Horton Park Avenue “certainly isn’t an immediate option.”
The club is second from bottom in the Conference North.