What did we learn from Alonso's first Chelsea game?

Sky Sports' Ron Walker:There's always a word of caution about reading too much into the opening game of pre-season, especially with so many first-team players missing for Chelsea.But there's certainly a few takeaways from Xabi Alonso's debut in the dugout...Flexible formation - Chelsea defended in a four but with the ball, Landon Emenalo bombed forward down the left and often overlapped Dastan Satpaev down that flank. It did leave Chelsea open at the back, though.Youngsters impress - Both Reggie Watson and Reggie Walsh looked sharp and linked up well in midfield, with the former the only player to complete 90 minutes. Mahdi Nicoll-Jazuli also enjoyed a bright half-time cameo while Dastan Satpaev started brightly but fadedFirst-teamers' sharpness - A number of Chelsea regulars only got half an hour to show their stuff but Cole Palmer and Joao Pedro looked immediately up to speed and had little rust to shake off. You can't argue with a nine-minute hat-trickDefensive concerns - Josh Acheampong and Tosin were two of Chelsea's more senior players to start the game in Sydney but both found life difficult against a side who finished bottom of the A League last season. They were offered little cover by the visitors' midfield at times.