Chelsea interim manager Guus Hiddink said he likes his players to show fight and emotion, claiming it raises their level of playing.
Oscar and Diego Costa were involved in a training ground bust-up on Thursday, with Hiddink confirming they buried the hatchet soon afterwards.
Midfielder Oscar started the row with a strong challenge on Costa before the Spain international gave it back as good as he got, something that Hiddink likes to see in his players.
"When this guy puts the emotion in, then automatically his level of plays rises, and that is encouraging," he said.
"It was the two bulls - I don't like when they hit, but with the intensity of the training session -- we had a very sharp training session and it was on the edge.
"When you have to push people, then the motivation is too low. So I like it more when I have to be alert to what happens. Then, [I say] 'Come on, guys. Please. This is not done at a big club -- or any club.'"
Hiddink recalled previous incidents in his managerial career, but said it is all part of the job to react and solve those situations.
"If you go through your own career, you can have four, five, six times when you could have incidents which the manager has to manage, to solve.
"In my first spell at PSV Eindhoven, where we had a very strong team - we went all the way through the European Cup at the time - I had very strong characters, like Eric Gerets, like Soren Lerby, like Ronald Koeman, who were very eager to win and they liked to go on the edge.
"As a manager, you have to react rather well."