Rumours have resurfaced that Vialli's stay might be a short one, that he is being used to lure big-name players before moving on in the summer, but the Italian's taste for leadership so far would suggest a longer stay.
Vialli's decision to drop himself and Mark Hughes, made after long consultation with his right- and left-hand man Graham Rix, in favour of a 4-4-2 formation with a two-man forward line led by Tore Andre Flo, paid off within 10 minutes of the start of the match against Real Betis as the Norwegian netted the goals which should see Chelsea through to the semi-finals.
But Vialli also recognises that tactics do not necessarily win matches. The Italian knows that players do and his greater skill, in contrast to the often aloof approach adopted by Gullit, is evidently his ability to foster camaraderie and team spirit. Footballers always boast about "great team spirit" whatever their plight, but Chelsea players do not even have to say it at the moment.
The eve-of-game kickabout at the Vicente Calderon Stadium illustrated the relaxed atmosphere Vialli's appointment has helped restore to the club. The players laughed and joked, often at their own expense, but still put in the necessary concentrated effort. Hard work is a feature of Vialli training sessions, as much as the fun. "Things have not changed a great deal, but we run and sprint a lot more in training now. It can be hard, but it's good," Flo said.
Vialli had already revealed his game-plan to his players by the time of the training session, and this appears to have played a crucial part in his success on Thursday night, as well as being an indication of his potential to succeed at Stamford Bridge for the rest of the season and, with hope, beyond.
The Dutch goalkeeper Ed De Goey, again a key man in Chelsea's victory, knew Gullit well as a club and country team-mate. He said that there were marked similarities between his two most recent bosses and added that Vialli's stature in the game meant he was well equipped to deal with the European adventure so soon in his new career. De Goey said: "Vialli is coping very well with the changes in his life and the transition does not seem to have affected him in terms of pressure. Ruud is a relaxed person, but I think Luca is more laid-back and that gets through to the players. He also talks to us a lot more and takes the trouble to explain his thoughts and plans. He doesn't just put up the team sheet and say to everybody: 'Get on with it'."
The team changes, made after two successive Premiership defeats had prompted immediate questions about Vialli's abilities as a coach, may have come as a shock to the Betis side but at least they did not to the Chelsea players. De Goey said: "He told us in detail of his plans the day before the game and explained why he was making the changes and what he wanted us to do."
Betis's scorer, Alfonso, admitted afterwards that Vialli's tactical master- stroke had the Spaniards on the back foot from the kick-off. Alfonso said: "We were worried all week about the Chelsea attack and our preparations had been geared around a Chelsea side of Hughes, Zola and Vialli playing together up front. But he caught us out by playing Flo. By the time we found out what Flo was like, it was too late for us."
Alfonso's second-half goal does, however, give Betis some hope for when they meet in the second leg at Stamford Bridge. But the bookmakers make Chelsea favourites to win the cup outright and their two away goals mean they can even afford to lose 1-0 and still progress to the semi-finals.
Champagne bottles were duly cracked open on Chelsea's charter flight home from Seville, just as they had been in the dressing-room before Vialli's first game as manager just over two weeks ago, and there were still smiles all round when they touched down at Heathrow at 3am. No doubt, Vialli already has a magnum or two on ice for the second leg and maybe he can fulfil his aim of being both good cop and bad cop after all.