Brazilian media reported that 57-year-old Jose Agostinho Becker had drowned after going for a swim on his property in the city of Lavras do Sul, in the south of the country.
Mourinho said the 34-year-old remained one of the best goalkeepers in the world, comparing his errors with those of Liverpool's Alisson Becker.
Premier League: Manchester City beat Tottenham to extend lead to seven points; Liverpool stunned by Leicester
Pep Guardiola's side stretched their English top-flight record run to 16 successive victories in all competitions.
Liverpool had not tasted a league defeat at Anfield since April 2017.
Premier League: Manchester United retain top spot after Liverpool draw, Manchester City up to second
Manchester United are two points clear of second placed Manchester City, who have a game in hand, and third placed Leicester.
Chelsea's Kepa had the lowest save percentage of any goalkeeper to play at least 10 games in the Premier League last season, while Liverpool's Alisson has been instrumental in the Reds' dominance over the past couple of seasons.
WHO logs into TikTok to spread awareness on coronavirus; Deepika Padukone, Sachin Tendulkar accept safe hands challenge
Veteran Bollywood actor Amitabh Bachchan was seen raising awareness about the highly infectious disease in a video by the Ministry of Health and Family Welfare.
Premier League: Liverpool fight back against West Ham to win five-goal thriller, need 12 points to lift maiden title in PL era
Trailing 2-1 late in the second half, West Ham keeper Lukasz Fabianski was twice at fault as Mohamed Salah and Sadio Mane ensured Liverpool prevailed to equal the record of 18 consecutive top-flight wins set by Manchester City in 2017.
Premier League: Virgil van Dijk, Mohamed Salah extend Liverpool's unbeaten record with thumping win over Manchester United
It's been a 30-year wait but there is no longer any trepidation from the Liverpool supporters as their team has moved 16 points in front at the Premier League summit.
FIFA Club World Cup 2019: 'Exhausted' Jurgen Klopp hails 'outstanding' Liverpool after narrow win over Flamengo in final
Liverpool manager Jurgen Klopp hailed his team’s Club World Cup victory over Flamengo as a “wonderful night” and said the European champions had again shown the power of their self-belief.
FIFA Club World Cup 2019: Liverpool beat Flamengo 1-0 with Firmino extra-time strike to lift maiden international title
An extra-time goal from Roberto Firmino gave Liverpool a 1-0 victory over Brazil’s Flamengo to win the Club World Cup at the Khalifa International stadium on Saturday.
Liverpool's hunger for titles like "an addiction to win one more medal," says midfielder Adam Lallana
Liverpool midfielder Adam Lallana says their quest for silverware was like “an addiction” as they chase a maiden Club World Cup crown to add to last season’s Champions League success.
Premier League: Liverpool's Alisson Becker says they don't want to lose league title to Manchester City again
Liverpool do not want to experience a repeat of last season when they narrowly lost the Premier League title race to Manchester City and will look to take all three points when the champions visit on Sunday, goalkeeper Alisson Becker has said.
Premier League: Liverpool's Alisson focused on 'getting back confidence' after returning to training from calf injury
Alisson was carried off in Liverpool's 4-1 victory over Norwich on the opening night of the Premier League season on 9 August.
Premier League: Liverpool manager Jurgen Klopp not planning on rushing injured goalkeeper Alisson Becker back into squad
Brazilian goalkeeper Alisson has been sidelined since suffering the injury in Liverpool's first Premier League game of the season against Norwich in August.
Premier League: Liverpool suffer huge setback after goalkeeper Adrian injures ankle following Super Cup victory
Adrian was brought in late in the off-season following Simon Mignolet's departure for Club Brugge in Belgium.
Premier League: Liverpool goalkeeper Alisson Becker ruled out for 'next few weeks' due to calf injury, informs Jurgen Klopp
Klopp revealed on Monday that he does not expect the 26-year-old Brazil international to be available for several weeks.
UEFA Super Cup: Liverpool's Alisson ruled out of Chelsea clash after suffering calf injury in Premier League opener
Alisson Becker suffered a calf injury in Liverpool's 4-1 Premier League opening day win over Norwich City as he slipped trying to play the ball out.
Norwich captain Grant Hanley's early own goal set the tone for what could be a long season for the Canaries before Mohamed Salah, Virgil van Dijk and Divock Origi netted as Liverpool shot out of the blocks.
Champions League: Mohamed Salah, Divock Origi help Liverpool beat Tottenham Hotspur, clinch sixth title
Mohamed Salah scored one of the fastest ever goals in a Champions League final and Divock Origi struck late as Liverpool won the title for the sixth time.