Mourinho was handed the reins at Old Trafford last summer and endured a miserable campaign in the league that saw them finish sixth, despite picking up the Europa League and the EFL Cup.
Former Liverpool boss Souness remains adamant that Mourinho is not suited to the club, and feels that he was only appointed because of Pep Guardiola’s arrival in Manchester.
“I didn’t think Mourinho was right for United and I said that from day one,” he told Yahoo Sport.
“Because Guardiola was coming in at Manchester City, the people making decisions at Old Trafford felt compelled to go and get a big name manager and they ended up with Jose.
“He has taken on a very difficult job at United and struggled to find his best eleven last season, if he ever found it.
“Mourinho is used to winning league titles and finishing where he did last season in the Premier League will not be acceptable, but it won’t be easy to put it right.”
Guardiola did not have the most impressive of seasons either, finishing 15 points behind champions Chelsea in third.
And Souness was keen to acknowledge that both managers would be under pressure next season.
“We all thought it would be Guardiola v Mourinho doing battle at the top of the table last season, but City and United never even came close to getting into the title mix,” he added.
“Now they will be under pressure like never before because they are working for owners who expect to be challenging for the title.
“The record these two guys have confirms they are great managers, but they have probably taken on the biggest challenges of their career in these two jobs and they have to respond to the task.”
