Under-21s coach Skubala previewed Wednesday's Premier League game at Manchester United following Marsch's dismissal on Monday after less than a year in the role.
It is understood Leeds had a shortlist in place and interviews have already started at Elland Road for the club's 13th head coach in less than 10 years.
Skubala said: "This is temporary, I'll go back to my old role when this is done. I'm just getting through this first game. Whatever happens between tomorrow and Sunday remains to be seen.
"I've seen change quite a lot so it's important to be calm. It's been busy, but it's a good challenge. The owners are working really hard behind the scenes to find the solution."
Skubala was director of football at Loughborough University and then worked at the FA, culminating as head coach of England Under-18s, before being appointed in his Under-21s role at Thorp Arch last July.
He will be joined in the dugout at Old Trafford tomorrow by development coach Paco Gallardo and Chris Armas, who was appointed as Marsch's assistant at the end of last month.
Armas will be returning to Old Trafford, where he worked as assistant to Ralf Rangnick until the end of last season when Erik ten Hag took over.
Marsch was sacked after Sunday's 1-0 defeat at Nottingham Forest left Leeds in 17th place, outside the bottom three on goal difference.
Skubala said: "Yesterday, (director of football) Victor (Orta), (chief executive) Angus (Kinnear) and the board came to see Jesse.
"It was a discussion that had to take place and after that they pulled me and a few staff members in to talk about how to get through this period.
"We had meetings and we put a plan together that we thought was the best thing to do."
Vallecano head coach Iraola, 40, is understood to be among the candidates Leeds are keen to speak to, along with West Brom head coach Carlos Corberan, who worked under Marcelo Bielsa at Elland Road.
Iraola's reputation has grown in LaLiga during his two-and-a-half years as a coach with unfashionable Vallecano, who he has guided to fifth place in the table.
Corberan remains the bookmakers' favourite to succeed Marsch - the Spaniard has guided West Brom from 23rd to sixth in the Championship since arriving in October - while Celtic boss Ange Postecoglou and Mauricio Pochettino are high on the list.
Leeds, without a league win since November 5, take on arch-rivals Manchester United twice in the space of five days, with the return fixture due at Elland Road on Sunday.
Club-record signing Georginio Rutter and another January arrival, USA midfielder Weston McKennie, are hoping to make their first league starts.
Skubala said several unnamed players were carrying knocks and would be assessed, while Rodrigo (ankle/tibia), Adam Forshaw (hip) and Stuart Dallas (broken femur) remain long-term absentees.
"I think it's every coach's dream," Skubala said of his pending role at Old Trafford. "I'll be up for this as much as the other players and coaching staff. It's very exciting.
"We have a good staff team. We have 24 hours. We have one session this afternoon that we've prepared.
"I think there may be a few little tweaks and differences, but we have to make sure players understand the game plan. We can't be passive, but we need to be pragmatic."