Which stars need to shine this season: Real Madrid, Barcelona, Man Utd, PSG

Football leagues around Europe are gearing up for the new season and preseason training and friendlies are in full flow.

All eyes will be on the transfer window as clubs scramble to find the missing pieces, either in the starting lineup or to complete the squad.

The mega signings of the European summer saw England international Elliot Anderson switch Nottingham Forest for Manchester City and Ivory Coast’s Yan Diomande swap RB Leipzig for Real Madrid.

Rumours are rife that Rodri may be heading out of City with Barcelona poised.

It seems, however, as though it has been a quieter period on the transfer front, with perhaps one of the more settled summer squads across the continent than in previous years.

So, Al Jazeera Sport takes a look at which players are most crucial to their teams’ success in the leagues across Europe – and why statistics back that up.

After an underwhelming World Cup, Declan Rice will be desperate to renew his importance to Arsenal. The 27-year-old, who arrived in North London from West Ham, was central to the Gunners’ defensive set up, ball retention and, crucially, their extraordinary set-piece threat last season. The Gunners scored a league-high 24 goals from set-pieces, with eight coming from Rice deliveries and three producing direct assists. The arrival in midfield of Bruno Guimaraes from Newcastle , should lighten the load for Rice, but it will not diminish his importance to the title defence.

The heartbeat of Manchester United since he joined the club, Bruno Fernandes may perhaps be the player hardest for any of the clubs on this list to replace should he sustain a long-term injury. The attacking midfielder was arguably the best player in his position in the world last season, as he produced a remarkable 21 Premier League assists – a single-season record – while also ranking first for chances created and through balls. His 45 chances created were also the most in the division, while his expected assists ranked second. Fernandes is not simply contributing goals and assists; he is creating a huge proportion of United’s attacking opportunities. If United are to challenge consistently, maintaining that level will be key. His workload in midfield may be affected by the departure of Brazilian midfielder Casemiro – how United fill that void is likely to influence the performance of Fernandes.