They have not played together for almost a year after Lydiate fractured his ankle in September.
But the Racing Metro-bound flanker is eager to join forces with the British & Irish Lions captain once again.
"We've been friends for a while now and are good mates off the field," said Lydiate.
"I haven't played with him for a year and hopefully we'll get a chance somewhere along the tour to play together again.
"From my experience of playing with Sam, I think he is really good over the ball. You saw that especially when we had a lot of time together at the World Cup.
"In the first game against South Africa, I can't remember how many turnovers he had. He's so strong over the ball.
"That's what you want your seven to do. If they are not turning ball over, they are slowing everything down, stopping the opposition from playing.
"On the same hand then you've got Justin who is a quality player in himself and Sean who is a different type of seven. It's a real strong back row going out there, which is vital to a successful team."
Having missed the majority of the season and only returned to action at the end of March, Lydiate is thrilled just to be included in Warren Gatland's 37-man squad.
And he is loving every minute of life as a Lions and cannot wait to jet Down Under.
"I didn't expect this at all because I obviously missed all the international rugby this year," said Lydiate.
"I'm just chuffed to bits and honoured to be here and I've got to prove my worth now.
"I've been loving it since I've been here. It's the next step up from international rugby and I'm feeling that in the training as well.
"The accuracy that the players bring to it is unbelievable. It's a really good environment to be in.
"I count my blessings at being here, to be honest. But when you get into camp and into training, you are here to do a job, so you are just trying to absorb everything and take everything on board as quick as you can.
"My ankle is good. It's stiff in the morning but it's no different from the other one. Just strap it and I'm good to go. I'm quite happy.
"I've played five games now and it seems to be going well in training. I couldn't ask for anything better.
"It would have been nice to get another couple of matches just to get up to the speed of international rugby, which I haven't played this year.
"When I came back, I was a bit heavy. But training at the intensity we are, I'm starting to run at my normal weight.
"I'm feeling quite fit at the minute and just gelling with the boys now."