Costa looked like he would be leaving Chelsea earlier this month.
A £30million-a-year offer from Chinese side Tianjin Quanjian caused tension between the stirker and manager Antonio Conte.
Conte dropped the Spain international for the 3-0 win at Leicester, but the 28-year-old has since returned to the fold and featured in the wins over Hull and Brentford.
Pedro has revealed Chelsea are delighted to have Diego Costa back
And Pedro has now revealed how Costa has spoken to his team-mates to clarify his commitment to the Blues.
"We are happy for having Diego back,” Pedro told IBTimes.
“Diego is a very important player for this team.
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Pedro revealed Diego Costa spoke to his team-mates to clarify his commitment to Chelsea
“Whenever he is inside pitch, scoring goals as he is doing this season and playing at this level, is great for the team.
"We simply remained calmed with him and he also spoke in the dressing room [to explain the situation].
“We are all behind him and he is very involved with the rest of the group.
“He is committed and we are all fighting for the same goal."