The 32-year-old was diagnosed in March, but the new Villa manager has moved quickly to confirm that Petrov will continue in the role he has held for three years.
The pair were team mates at Celtic after the Bulgarian moved to Parkhead from CSKA Sofia in 1999, and Lambert feels Petrov's influence will be a key factor in his new regime at Villa Park.
"Stiliyan is still club captain," Lambert declared. "He is a huge influence on this football club. I was with him for a few hours, he was doing great and I'm looking forward to going back down to see him.
"I played with him when he was only 19 and he first came over to Scotland. At the time I was told, we were on our way to Fulham. I was just devastated. I couldn't believe it.
"He's such a strong lad and a terrific guy. Hopefully he'll be ok. Your health is more important than anything. I'm sure he'll beat it."
Lambert is also keen to hang on to the top-rated members of his squad as he looks towards improving Villa's fortunes following a poor season that ended with the Villains finishing 16th in the Premier League and Alex McLeish losing his job.
"This club has international footballers I'd like to keep here," added the 42-year-old.
"I think we have to prove we can keep them to give us a foothold. I will do everything I can to make this club as strong as it can be."
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
The adidas Nitrocharge is the most talked about new cleat in years. It was released on May 15 and will take your pitch by storm.
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
The push for more color on their cleats, adidas has added the infrared colorway to the adiZero f50 Line.
The new PUMA evoSPEED 1.2 FG. A great new soccer cleat with classic look and first time for PUMA to be on the cleat.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.
Ajax has released their away soccer jersey for the 2013/14 season. Get in the Gear.