Lahm called time on his career with Germany less than a week after lifting the World Cup in Brazil, having made 113 appearances in the past 10 years.
The Bayern Munich skipper featured in three World Cups and three European Championships after making his international bow in 2004, and while Matthaus feels he will be sorely missed at international level, the 1990 World Cup-winning captain is happy at the prospect of having the 30-year-old commit solely to his club.
"For Bayern, it is certainly good. Philipp has tried to take his foot off the accelerator a bit to maintain fitness for other important tasks," he told Sky Sport News.
"He was a great captain who has brought top performances over the years and that deserves great recognition.
"Now [he will get] a bit more privacy, less pressure in the public, including some more breaks and less games, and full fitness for Bayern."
Lahm was only 37 appearances behind reaching Matthaus' record of 150 for Germany.
With Joachim Low now searching for a replacement captain, Matthaus predicted Bastian Schweinsteiger would be the one to step up.
"You do not need to think twice. I assume that Bastian Schweinsteiger takes over the captaincy, he was also vice-captain," Matthaus added.
"Sami Khedira and Manuel Neuer will then move up."