The former Bhoys shotstopper returned to Polish international duty this week to captain his country to a 0-0 draw against an experimental Germany side in a friendly in Hamburg between two of Scotland's Euro 2016 foes.
Boruc had an outstanding World Cup while at Parkhead in 2006 and he's delighted highly-rated Forster will follow in his footsteps after being named this week for England's Brazil 2014 squad.
And the 34-year-old Southampton star, who has himself enjoyed a superb season in the Barclays Premier League, has been impressed with the man who replaced him as Parkhead No.1.
Boruc said: "I am very pleased for Fraser, it's fantastic for him that he is going to go to the World Cup. And it is fantastic for all of the Celtic supporters as well.
"It's a huge thing for Celtic Football Club as well to have him there so I am glad for him.
"Hopefully he will play, but it's not going to be easy for him to play as England have good keepers.
"But just being there is really big for him and I am pleased to see another Celtic goalkeeper going to a World Cup.
"I watch Celtic games on TV when I can and I obviously watched him in the Champions League and I can see he is a very good goalkeeper.
"So I am not surprised he has been selected. Others might be, but I am certainly not."
Boruc was recalled to international duty in the the absence of Arsenal duo Lukasz Fabianski and Wojciech Szczesny, who are preparing for this week's FA Cup final.
He would love a chance to play against Scotland in this year's Euro qualifiers.
And he admits he's been impressed with the transformation in Gordon Strachan's side after Scotland defeated the Poles in a Warsaw friendly in March.
Boruc said: "Scotland have improved recently, but I expected that to happen.
"I know Gordon Strachan pretty well and I know he is a really good manager.
"The quality of players they have right now is very good as well and that obviously helps.
"But we will see what happens when the time comes around to play them in the qualifiers. They beat us in a friendly - but that was a friendly."
Boruc is unsure if he will still be involved in the international set-up when the Scots return to Warsaw in October.
He said: "It was a proud moment for me to lead my country against Germany, it's always a pleasure for me to do that.
"I don't know if I will be involved when we play against Scotland in October - that's up to the manager."