The centre-back has revealed his delight at seeing the defender arrive at Camp Nou following their struggles at the back last term
The size of the fee for the 30-year-old has raised eyebrows but Pique, who is set to start the season alongside the Frenchman at centre-back, believes the signing is a much needed one.
"We needed to fill that position," the Spain international said.
"Whenever Mathieu has played for Valencia in that position he has always done well and I'm delighted with his move."
Pique, who endured a miserable summer following Spain's group stage exit at the World Cup, on the back of Barcelona's trophyless season, also commented on Xavi's stay and the departure of Cesc Fabregas.
"Despite all the rumours he was going to go, the end has not happened," the 27-year-old continued. "I've always thought that Xavi still has a part to play on the team.
"Cesc wanted to feel important and Barcelona decided to take the money. Chelsea have bought a good player."