Arsenal manager Mikel Arteta has brushed aside questions about Chelsea's unconventional training preparations ahead of Sunday's Premier League London derby at the Emirates Stadium, calling the use of rugby tackle pads a routine practice seen across clubs.

Photos and reports emerging from Chelsea's Cobham training ground this week showed players including Joao Pedro, Valentin Barco, Pep Chavarria, and Josh Acheampong holding large crash pads while their teammates charged at full force into them. Former All Black star and experienced rugby coach Willie Isa was reportedly on hand to oversee elements of the drill.

Set-piece threat looms large

The sessions are widely seen as targeted preparation for Arsenal's formidable set-piece threat. The reigning Premier League champions were the most effective dead-ball side in England last season, netting 22 goals from corners and other set-piece situations — a record that demands respect from any opponent.

Manager Xabi Alonso appears to be taking no chances, drilling his squad on the physical, aerial duels and the aggressive