Chelsea boss Thomas Tuchel insists they will only sign players they are 'absolutely sure' about to not risk bringing in bad influences to the 'top guys in the dressing room' they have already.
Tuchel inherited a squad back in January that was low in confidence and has turned them into a side who are hard to beat which has seen them go unbeaten in his first 14 games in charge.
Chelsea are flying and speculation of their transfer plans this summer have already started being reported, including Borussia Dortmund forward Erling Haaland - Tuchel refused to be drawn on such links.
Despite new signings being expected at Stamford Bridge this summer, Tuchel made it clear that he would still be happy if his side didn't bring in any new additions.
However, he insisted that he won't risk the morale of the group and Chelsea have to be 'absolutely sure' on players this summer if they are to be signed.
He told reporters ahead of the clash against West Brom: “Our players are happy to be with us.
"This is the most important thing. And don’t forget that we have young guys up front and they will get better. I am convinced [by that] and it is my job to make them better.
"Honestly, if we have a transfer ban [from] tomorrow, I would be a happy coach next season. We can push this team to the next limit and level. I have ideas, of course, of how to maybe improve this team, but it’s very, very difficult.
“First of all we have a very strong group with a strong bond, and this means that we need excellent characters.
"That is the most important thing because we have top guys in the dressing room and I won’t allow anybody to ruin that and have a bad influence in there. So we have to be absolutely sure.
"The work ethic, the mentality, the attitude towards training and games is outstanding, and it has to stay like this.
"There has to stay a strong bond in the dressing room. It’s not like a puzzle where you take out a piece and put the next piece in. This is a complex situation, every transfer market is."