Mickey Lewis agreed to take over as caretaker-manager on Saturday night and will face the media this afternoon ahead of tomorrow’s trip to Exeter City.
The U’s are well placed in Sky Bet League Two’s play-off places, but with seven games in the next 26 days they can ill-afford a slump in form.
Lewis has experience of the role, taking the helm for three months at United from October 1999.
Lenagan has confidence the staff will cope while the search goes on for Wilder’s replacement.
He said: “The very fortunate thing is we have a superb structure in terms of assistant mangers, conditioning and physio. I’m not at all concerned about that aspect of it.
“You always consider what the options might be, but in Mickey Lewis in particular we’ve got a guy who has done stand-in management before. Mickey is more than capable of handling the team over a few matches.
“We have other people in the background helping and we’ll be inundated by people, who want the job, of the right calibre.
“It’s just a pity that it’s come to this, obviously at this particular time, but from an Oxford viewpoint I feel very positively about the future.
“I think with the squad and the background staff we have got in coaching, and all of the other areas, I don’t feel in any way exposed going forward.”
He added: “I feel confident we can weather the next few weeks positively and that we will get an excellent manager going forward.”
Lenagan’s intention is to keep the backroom staff and appoint a manager who will be happy to work with them.
It is not known whether Wilder will attempt to take any of his staff with him up the A43.
United’s chairman is hopeful their connection to the club will outweigh any loyalty to the former manager.
“I don’t worry about it,” Lenagan said.
“You’re never absolutely sure, but whilst they respect Chris and have enjoyed working with Chris they have a large affinity for Oxford and we would like them to stay.
“I’ve never been one for bringing in a new manager and a whole team, I have made that very clear.
“So as far as I’m concerned Mickey Lewis and Andy Melville are very important parts going forward, as are Alasdair Lane and our physio (Andy Lord).
“It’s very important to us that those people continue.
“There’s always a little bit of disruption when a manager leaves, but we have good systems and structures in place and I’m sure we will manage well.”