Any doubts José Mourinho may have harboured over the condition of Chelsea's old guard have been allayed in his first week back with the squad after the manager claimed the more seasoned campaigners had been "training like animals" since returning to work.

Mourinho will oversee the first game of his second spell in charge of Chelsea on Wednesday, against a Singha All Star XI, with John Terry, Petr Cech, Michael Essien, Frank Lampard and Ashley Cole all to start at the Rajamangala national stadium. The quintet featured under his stewardship last time around and, while the manager has already backed Chelsea's young talent to thrive over the season ahead, he will lean on familiar figures to inspire a title challenge.

Terry, who has entered the final year of his contract at Stamford Bridge, had stayed behind to practise after training the night before at the International School of Bangkok and was the first out-field player on to the turf at the national arena. "The good thing with my previous players is that what I see makes me very happy," Mourinho said. "I don't see them any different to before. And when I see Terry, Cole, Lampard, the way they are working at 32, 32, 35, it's easy for me to control the group and demand the same from the other guys. I can say: 'Look at them: they don't miss one minute; they are training like animals; they compete. So you, who are 18, 19, 21, don't tell me you can't do it.'

"It's fantastic. I'm very happy. They know me. They know that I'm not going to make their lives easy but that I am going to give them something back. And, because they know me, from the first day they never questioned that situation and just worked hard. It's good for me because they are ready, all of them. The group is good and the other six boys (who have been given more time off after the Confederations Cup) will find something good when they come. They will feel it, what we are doing here. When the Matas, Oscars and Luizs come back they will smell immediately that we are doing something. It will be easy for them to come in."

Training was conducted in front of around 4,000 supporters on Tuesday – the game has been sold out at around 48,000, with tickets priced up to £64 – with Mourinho's upbeat mood reflecting the optimism that has enveloped this club.

"My wife was right," he said when asked if he felt revitalised to be back in charge after his last tempestuous months at Real Madrid. "She doesn't talk about football, but she told me a few times in Madrid that I needed to be happy to be able to give my best. I needed to be happy to be motivated, to spend my time organising training sessions and enjoying the sessions, to enjoy being with the players outside the training sessions – and I'm having all of this here."

Mourinho remains in the market for a striker and would ideally like to secure the recruit well before Chelsea's start to the Premier League season on 18 August. Yet any signing would apparently not jeopardise Fernando Torres' standing with the manager reluctant to part with any of his senior squad.

"First of all I don't want the club to sell," he said. "We are very much on board and connected, me and the board and the owner, and we don't need to sell players. We are happy with the group we have. We are not on this market pressure. If something happens it will happen naturally but we are in a position where we are not worried."

He intends to tweak his favoured 4-3-3 formation for particular matches, occasionally using two defensive-minded deep-lying midfielders while retaining the flexibility to be more expansive. Juan Mata – who is still on leave along with Torres, César Azpilicueta, Mikel John Obi, David Luiz and Oscar – could operate as a playmaker or even be utilised on the right of an attacking three behind a forward, though the manager admitted he needed "to get to know him better".

"We will play 4-2-3-1 in the first game, my favourite system, though sometimes I change the triangle and play with one in front of the defenders and two players up," Mourinho said. "Other times I play with double midfielders and a No10. This is a team where we have not one or two but three or four players who like very much to be a No10: [Kevin] De Bruyne likes it, Oscar likes it, Mata likes it, [Eden] Hazard likes it. It is a natural system for all these players to play.

"But in another match I could change it. If we are losing, we might need to have two pure strikers. It is something we will work on because I would like to have this capacity to have it ready to play, independent of the players we have. Naturally, we will have four at the back and in my team, the attackers are attackers. Some guys say we play 4-2-3-1, blah blah blah blah, and sometimes the attackers have a defensive job so it is more like 4-5-1. But it is not 4-5-1, it is 4-3-3.

"With Mata, I need to get to know him better. I like sometimes to play with what I call 'wingers with the wrong foot' – right-footed men on the left and left-footed men on the right. He is the only left-footed player we have when we want to play with a winger on the right side, but the competition is hard. We will have Schurrle, De Bruyne, Mata, Oscar, Hazard and Moses for these three positions and so we have many more options than Chelsea had in the last year. These are crucial positions for me. I like these players to play with high intensity so to have five players for three positions is, I think, brilliant for me. It's fantastic."