Levein, the club's director of football, described finishing fifth in the Premiership, as "frustrating and a tad disappointing".
"I've got high hopes for him [Cathro]," Levein said. "This is a tough place to manage, as I know myself.
"The thing about here is the players like him."
Levein points to mistakes in the January transfer window which saw Hearts sign nine players - six of whom have since left the club - as a chief reason for the underwhelming league campaign.
Dylan Bikey, Tasos Avlonitis, Lennard Sowah, Andraz Struna and Alexandros Tziolis are all moving on while Moha Choulay is returning to parent club Stoke City.
"Rushed is probably a fair assessment," Levein explained.
"We've had six transfer windows since the club came out of administration [in 2014]. Four of them have been really good, the last two haven't been particularly good.
"In hindsight, should we have given longer-term contracts to some of those players? The answer is probably no.
"The fact we gave them short-term contracts has allowed us to still be in a position to be able to strengthen this summer and repair some of the damage."
Levein says the "furore" surrounding 30-year-old Cathro since his arrival has been tough for the young head coach to deal with, but says the players enjoy working under him and will improve next season.
"For him to be a real success here we need to give him time and let him understand what this is all about," Levein explained. "Then we can let him go and play how he wants to play, but we need to fix some other things first.
"His problem early on has been understanding Scottish football, not understanding how he wants to play.
"In this country just now, Celtic are in a class of their own, Rangers play a different style of football to other teams, but the rest play the same.
"If you can't deal with long balls, second balls, wide crosses, then you can't impose yourself on the match.
"His early experiences have been about understanding that part of it. Once he deals with that part of it I think it will allow his coaching abilities to come to the fore."

Mr Chand died in a hospital in Chandigarh  after suffering a heart attack on Friday, his son Anuj Saini told AFP news agency.
He used rubble from the city's construction to create sculptures at the 20-acre Chandigarh Rock Garden.
Mr Chand had no formal education and worked as a road inspector in the city.
"I started building this garden as a hobby" in the 1950s, he said in an interview with AFP in December.
"I had many ideas, I was thinking all the time... I saw beauty and art in what people said was junk."
The rock garden was opened in 1976 and it now attracts hundreds of visitors a day.
"He passed away a little after midnight. He had been in hospital for the past few days due to ill health," said Mr Saini.
India's Prime Minister Narendra Modi led the tributes, saying Mr Chand would "always be remembered for his artistic genius".

Of 151 drivers stopped by Thames Valley Police, 137 were using their phone.
The operation was carried out in Berkshire, Oxfordshire and Hampshire.
An unmarked lorry was used to spot offending motorists during a five-day period in 2016. Police said they were disappointed with the figures.
"Sadly we have seen many examples over the last 12 months of lives lost unnecessarily because a driver has not had their full attention on the road," Sgt Paul Diamond, who led the operation, said.
The joint operation with Hampshire Constabulary was carried out on the A34, M40, M4, M27 and M3.
In August last year, four people died on the A34 on the Oxfordshire/Berkshire border when a lorry driver, who was scrolling through music selections on his phone, smashed into stationary traffic.
The driver, Tomasz Kroker, was jailed for 10 years.
Craig Levein retains "high hopes" for Ian Cathro's Hearts tenure but says the club will seek to "repair the damage" of recent transfer windows.
[NEXT_CONCEPT]
Indian artist Nek Chand who created a famous garden of sculptures in the northern city of Chandigarh has died, aged 90.
[NEXT_CONCEPT]
A van driver eating breakfast cereal on the M27 and an HGV driver shaving behind the wheel on the M4 were spotted by police in a crackdown on distracted motorists.