José Mourinho has said that, as reigning champions, Chelsea should be considered title favourites and have no excuses for not challenging this season as their manager, Antonio Conte, has replaced players sold this summer.

Chelsea’s championship defence began with last Saturday’s 3-2 home defeat by Burnley. Yet, despite this, Mourinho pointed to Conte’s moves in the market as evidence Chelsea remain strong. These include Monaco’s Tiémoué Bakayoko being bought before Nemanja Matic was allowed to depart for United, while the Portuguese pointed to how Conte is targeting Leicester City’s Danny Drinkwater to bolster midfield. The Italian has also brought in Álvaro Morata who was acquired with Diego Costa’s future still uncertain.

On Sunday United coasted past West Ham 4-0 at Old Trafford. Yet, asked if his team were more stable than all of their rivals, Mourinho said: “If they [rivals] have problems, the problems are going to finish in a couple of weeks because in a couple of weeks the market is closed and they don’t have problems any more.

“If they have, and I don’t know if they have but if they have, in a couple of weeks the problems are over. They have very good teams, very good players and I don’t see any reason for them not to be fighting for the title.

“When people say, for example, Chelsea lost an important midfield player [Matic], if you lose one but you buy Bakayoko and Drinkwater for example, what’s the problem? The problem is when you sell and you don’t buy. When you sell and you keep buying, what’s the problem? You are probably even stronger, so I think every top team in the Premier League is strong enough, is potentially strong enough with the financial situation to be fighting for everything and, when everybody is also in Europe, five in the Champions League and two in the Europa League, you have the top seven teams playing for everything and all of them are strong.

“For me the favourite is the champion. Always. Because for some reason [they were] the champion. It doesn’t mean you are going to win it – I think it is the stamp that you have when you are champion, it is that the next season you are the favourite. I just want to think that we go to every match and we only think about winning that match. I don’t go to any match this season thinking that the opponent is better than us, we are going to try to have a point. Probably a point will be an amazing result but we are not going to any match thinking that way. We go to every match trying to win. If we win, we win. If we don’t win, we don’t win.”

Romelu Lukaku, who scored twice against West Ham, and Marcus Rashford showed encouraging signs of an understanding in the win. “I feel that connection but I feel that connection with more players,” said Mourinho. “I feel [Anthony] Martial-Romelu is a good connection, I feel [Jesse] Lingard is a good connection, I feel [Henrikh] Mkhitaryan is a good connection.

“Romelu is a good player to play with. OK, a striker lives on numbers and it was because of Romelu’s numbers that we paid so much to have him. But a striker is not just numbers. It is the way he plays, the solutions he gives, the way he makes others play. I think he’s a good player to play with. People like Marcus, Martial, Mkhitaryan, to have that target man to play with is very good.”

Mourinho gave more details of the fourth new player he was targeting. He now thinks the addition may have to wait until the winter window, at earliest. “I have faith in him [Martial], said the manager. “Probably the player I was looking for wasn’t a pure winger because I have pure wingers. Probably the player I was looking for was a player that allows me to play with three in the [forward line] with three at the back and have a wing-back.

“As a pure attacking player, Anthony is a good player. I believe he’s one of the players who is going to have a better season this season than the previous season. I look at some of my players and I’m sure that some of them will be better this season than they were last season, and Anthony is that for sure.”