Antonio Conte is determined to ensure his English champions do not suffer another “Mourinho season” and slump again after winning the Premier League.

Chelsea won the title in 2014-15 under José Mourinho – now in charge of Manchester United – when he returned to Stamford Bridge for a second spell as manager. However, Chelsea picked up just 11 points from their first 12 league games the following season and Mourinho departed in December, with the London club finishing in mid-table under Guus Hiddink.

Conte, who won the Premier League at the first time of asking following his appointment last summer, is wary of letting his players repeat that fall from grace. Following Chelsea’s 2-1 friendly defeat to Inter in Singapore, the Italian told espn.co.uk: “We know the difficulty of the next season and for sure we want to avoid the Mourinho season with Chelsea. Two years ago the team ended the league in 10th place and we want to try to avoid this.”

Chelsea fly back to England on the back of two straight pre-season defeats – a 3-2 loss to Bayern Munich and the 2-1 reverse at the hands of Inter, for whom Stevan Jovetic and Ivan Perisic scored. Geoffrey Kondogbia then inadvertently recorded a consolation for Chelsea with his comical own goal.

Conte, who did oversee a 3-0 friendly win against Arsenal last week, blamed fatigue at the end of a month spent training and playing in hot conditions. “We played against two strong teams in Bayern Munich and Inter in a period that is very important as we are working very hard,” he said. “To play three games with the same players means you finish and are tired. We are tired, very tired.”

A number of other friendlies involving Premier League sides took place on Saturday. Liverpool’s record signing, Mo Salah, scored and Sadio Mané made his first appearance since April as the Reds cruised to a 3-0 friendly win over Hertha Berlin at the Olympiastadion.

Dominic Solanke opened the scoring in the 15th minute before Mané, back after knee surgery, set up Georginio Wijnaldum for Liverpool’s second just past the half-hour. Salah continued Liverpool’s impressive pre-season form when he completed the scoring in the 60th minute, finishing off a lofted pass from Philippe Coutinho.

West Brom suffered a 2-1 defeat to Slough Town, Tammy Abraham scored for Swansea City in their 2-0 win over Birmingham City, Watford drew 0-0 at Aston Villa, Wilfried Zaha scored Crystal Palace’s goal in their 1-1 draw with Metz and West Ham new boy Marko Arnautovic hit their first in a 2-2 draw with Werder Bremen.

Leicester City lost 1-0 to Wolves, Newcastle were defeated 2-1 by Mainz 05, Andre Gray netted the equaliser for Burnley in their 1-1 draw at Nottingham Forest, while Brighton and Hove Albion drew 1-1 with Norwich City. Meanwhile 9,000 Celtic fans travelled to the Stadium of Light to see their side thrash Sunderland 5-0.