Though Lewandowski surprisingly drew a blank against Hertha Berlin last weekend, the Poland international's ruthless goalscoring streak has been a key feature of Bayern's campaign, and his 20 league goals have fuelled his club's charge away from the chasing pack at the top of the Bundesliga table.
Watch: Lewandowski makes Bundesliga history in nine minutes against Wolfsburg.
Since arriving at Bayern from Borussia Dortmund in 2014, Lewandowski has risen to the level of one of the world's very best players, and though the team remains greater than the sum of its parts, Matthäus thinks the Poland international's worth to Bayern cannot be overstated.
"Maybe there are not many stars, but the Bavarians have a very strong squad. This is the strength of the team: the team is not very dependent on one player. Barcelona is on Messi, Real Madrid is on [Cristiano] Ronaldo and PSG is gambling on Neymar. At Bayern, all the players have the required quality.
"There is no such thing that absolutely everything depends on one player. But if I had to answer the question of who they depend on the most, I would point to Lewandowski," said Matthäus, who won seven Bundesliga titles in two spells at Bayern.
"'Lewy' makes a difference, he cannot be replaced. Robert is an important figure in Munich like Messi is in Barcelona. However, when Messi gets injured, the image of the Catalan game changes completely. Bayern does not have this problem. Lewandowski is a key player, but the team is not as set up for him as the Real game under Ronaldo or the tactics of PSG under Neymar."
With time advancing on even the peak-fit Lewandowski, who turns 30 next summer, Bayern moved to bring Sandro Wagner back to the club from Hoffenheim in January to lighten the load in leading the line. The Germany international forward is not a like-for-like replacement for Lewandowski, though, says Matthäus.
"He's a different type of player. Lewandowski fits perfectly into the Bayern system. Of course, Sandro is useful when the team plays long balls or often crosses into the penalty area. Wagner is a great player, he plays for the national team, but he doesn't have the impressive numbers Robert has because he often sits on the bench.
"He's also not of the same high quality. Lewandowski really is an exceptional player," Germany's 1990 FIFA World Cup-winning captain explained. "Lewandowski does not have an alternate who guarantees the same quality. The Pole is currently the best 9 in the world. Bayern will not find another player like that."
The same could be said of Arjen Robben and Franck Ribery, two players who have marked the history of the club. The pair are now both 34, out of contract next summer, and have Kingsley Coman providing serious competition for one of the places on the flanks of Jupp Heynckes' side.
Yet, Matthäus still sees them as having a place in the Bayern set-up next season, even if they will have to swallow their pride and accept more of a cameo role at the Allianz Arena.
Watch: See how Lewandowski handles 60 seconds under pressure.
"They are still in good shape, but because of their advanced age, they cannot play in every game and they should understand this. Heynckes does not sit on the bench to make players angry. He simply needs to conserve their strength accordingly," Matthäus explained, referring to 'Robbery' being in and out of the starting XI this season.
"The Dutchman and the Frenchman do not play as often as three or four years ago, that's normal. In addition, Bayern have Coman, who is also playing at a high level. However, I think that both Robben and Ribery will extend their contracts for another year."
Another major question mark hangs over the future of Heynckes, who will see the short-term deal he signed when he replaced Carlo Ancelotti in October expire at the end of June.
The 72-year-old's return for a fourth spell as coach has been an unqualified success with Bayern on course to complete a domestic double while they are already all but through to the UEFA Champions League quarter-finals after their stunning 5-0 dismissal of Besiktas JK last week.
"We do not have to talk about the results, everyone can see how well Bayern under the leadership of Heynckes is doing," said an admiring Matthäus, who played the first five years of his professional career under Heynckes at Borussia Mönchengladbach.
'Everyone is ready with Heynckes'
"No one expected, however, that the coach would have such a huge impact on the club. I'm not just talking about the team's victories, he has helped all of Bayern. The atmosphere in the club has improved greatly. Jupp perfectly manages the players' recovery, and thanks to that they are ready to play…He understands that if you want to win you have to have healthy players at your disposal.
"When injuries occur, the coach does not have much room for manoeuvre, and players from the starting XI put in less of an effort because there is no competition and no-one will take their place in the team. With Heynckes, everyone is ready."