Chelsea fans will expect Mourinho's return to Stamford Bridge be accompanied by a spending spree as Roman Abramovich arms his manager with the funds to reclaim a title they last won in 2010 when Carlo Ancelotti was at the helm.
Forward reinforcements top the shopping list, with Andre Schurrle of Bayer Leverkusen, Manchester City's Edin Dzeko and Fiorentina striker Stevan Jovetic reported to be on Mourinho's radar.
But the 50-year-old insists that drawing the best from his existing squad will be his most pressing concern and refuses to prioritise any silverware.
"We have to improve the team, but when I say improve the team people are already thinking about how many millions Chelsea will spend. When I say improve the team, I mean through work," he said,
"My work has to improve players and improve the team. If I don't do that I am not happy with myself. If after that we can improve the team by buying a couple of players it is fantastic, but I have to improve the team and the players with my work.
"The priority is to improve. In the last two years we have struggled in the Premier League.
"If Chelsea didn't win the Champions League then the club wouldn't have been in the competition this year. This year we had to fight until the last match to qualify.
"We must improve individually, improve collectively and improve the structure of the club around the football team, and try to win the next match.
"Which one is the next match? The Premier League? Let's go for the Premier League. If the next match is the FA Cup, let's go for the FA Cup. It's difficult for me to say something is the priority. The priority is to work hard, work professionally and make the team better."