Chelsea’s Xabi Alonso era has started with a bang.A riotous West London derby against Fulham at Craven Cottage delivered five goals, a hatful of chances, some thrilling attacking football and some very porous defending (and goalkeeping), before the visitors ultimately prevailed 3-2.Alonso will have been delighted by a debut goal for Morgan Rogers and a return to form for Cole Palmer, but alarmed by how easily Fulham were able to slice through his side at times.We discuss the major talking points.How impressive were Chelsea’s new signings?Only two of Chelsea’s nine first-team summer signings started at Craven Cottage, but they happened to be the most expensive acquisitions and the two “ready-made starters” the club had pledged to target ahead of Alonso’s debut season as manager.Morgan Rogers and Maxence Lacroix arrived at Stamford Bridge as proven Premier League performers, signed for chunky premiums that reflected their value to contribute immediately. Alonso and the Chelsea hierarchy will be delighted to see them both hit the ground running against Fulham.Lacroix, bought from Crystal Palace to bring leadership and physicality to Chelsea’s back line, won two booming headers in the first three minutes, one of which directly led to Joao Pedro’s opening goal. In the middle of Alonso’s back three he used the ball sensibly, defended calmly in space and always made his voice heard.Chelsea are unlikely to expect him to pop up in the opposition box in open play too often, but he did brilliantly to twist Jorge Cuenca inside out and draw Bernd Leno from his goal before cutting the ball back to gift-wrap a debut tap-in to Rogers.Which brings us to Chelsea’s marquee signing of the summer, the £117million man.Morgan Rogers with the celebration shared by his new teammate Cole Palmer (Mike Hewitt/Getty Images)Considering his limited involvement in preseason, Rogers dovetailed brilliantly with Palmer and Joao Pedro in a fierce but smart high press, nipping in to win the ball back high up the pitch on numerous occasions. His strength and ability to drive the ball added a different dimension to the front three, and he contributed the little things as well as rising in the big moments.Chelsea’s third goal underlined his willingness to do the less glamorous work, dropping deeper to try to flick Sanchez’s long kick on to Joao Pedro, though it was unclear even after a replay whether or not he made contact. It was much clearer throughout the game that his chemistry with Palmer goes well beyond a close friendship and translates to the pitch.This was game one, but the early evidence is that Rogers and Lacroix have both immediately improved Chelsea.