A team-mate and a friend, obviously, but one other description also applies. Stokes has been a close, on-field witness to the performances which should soon yield individual honours for one or both of his fellow Celtic men.
It is almost player of the year time. Some will advance a case for Fraser Forster, Stevie May, Barry Robson, Stuart Armstrong or perhaps Kris Boyd, and all have had commendable campaigns. But the overwhelming lobby will be on behalf of Commons and van Dijk. "Votes can be erratic," said Stokes. "But speaking personally I think it's hard to look past those two."
Two separate electorates are likely to come to exactly the same conclusion. On Thursday the players' union, PFA Scotland, will reveal its four-man shortlist for player of the year. At the end of the season, the Scottish Football Writers' Association will reveal its choice. It would be remarkable if anyone other than Celtic's top goalscorer, or their best defender, lifts either award.
They are chalk and cheese: forward and defender, creator and stopper, Scot and Dutchman, senior dressing-room man and newcomer, veteran of the Scottish scene and rookie. Each has powerful credentials to win. Stokes was able to offer insights on both. "Virgil has been outstanding this year but I'd probably give it to Kris, just for his goals and influence in games. He's been massive for us this season and has had the biggest impact of any player I can see in the league. He's a great player to play beside. I'm up alongside him and he sees a pass, and his goals have taken his game to a new level."
Stokes has scored 15 times in 41 appearances for Celtic but the responsibility to fill the void created by Gary Hooper's departure was shouldered most productively by Commons. From the same number of appearances the 30-year-old has already scored 27 goals.
"The boys at the back went on that run without conceding any goals and Virgil was a big part of that," Stokes continued. "He's been exceptional this season. But as a striker, playing alongside Kris, I think he probably deserves it. I think he's been pushed a bit further up the pitch this season and it's suited him. He's been on the end of everything. Any ball that broke there for three or four months just fell nicely for him. But you have to get yourself in the position to score those goals.
"He can strike a ball from anywhere on the pitch and has scored some incredible goals. He has added a different dimension to his game this season, pushing on that bit further and getting on the end of bits and pieces. Hopefully, he keeps it up because it's been a pleasure playing alongside him this season. Listen, playing at a club like this is great for attacking players.
"Kris is quite opinionated but he makes valid points. He's one of the senior boys. There's no doubt the younger boys look up to him. He's not the type to shout and roar but he will pull someone aside and if he has something to say he will say it. That's respected throughout the dressing room."
Respect for van Dijk came almost immediately. At just 22 and living in a new country for the first time in his life, let alone playing for a new club in an unfamiliar league, the centre-half's impact has been remarkable. Stokes described him as a defender who has it all, and then the compliments continued. "Virgil is one of the best young defenders I have seen in a long time.
"He's got the physique, he's strong, he's quick and his composure on the ball. He has a bit of everything and has been exceptional this year and a reason why we went so long this season undefeated. It can be difficult for people coming here, but he settled in right away. For a young lad, I can only see him getting an awful lot better.
"I think Virgil can go right to the very top. I genuinely do. Playing in the Champions League he looked comfortable and composed. The world is his oyster. I came through the ranks with quite a few of the young boys down at Arsenal and he'd be right up with the top of any of the boys I saw down south. Hopefully, he stays here a long time.
"We're not allowed to vote for team-mates as player of the year but it's difficult when you look at other teams because it's hard to gauge. We're playing on a Saturday so you only see highlights and the attacking players, the likes of Stevie May, scoring goals. It's hard to tell how other midfielders and defenders are doing. Watching highlights, it's just attacking moves and it can be hard to see the bigger picture. Given who we have played against, every time we have played against Barry Robson he's been a thorn in our sides. He's been exceptional and Niall McGinn is coming back into a bit of form."
Stokes was in front of the media yesterday to publicise an entirely different vote. Celtic fans are being encouraged to decide their team's best goal of the season, for the club's own end-of-season awards.
The 10 contenders are listed on the official Celtic website. One of them was scored by Stokes himself against Aberdeen in the Scottish Cup but his own vote would go elsewhere.
"I'd probably vote for James Forrest's goal against Shakhter Karagandy. I set that up, I put it on a plate for him. He hasn't shut up about it since . . ."