The centre-back duo have been criticised often over the past few seasons for being liabilities due to defensive mistakes.
But after restricting Wolves to just one shot on target in Saturday's 2-0 win, Martinez says he is delighted with his defenders.
"Now, we have structure, we have a gameplan, we have game management and the defence looks stronger and stronger," Martinez told Sky Sports.
"Believe me, David and Musti are top players. David has been at the top for so many years and it's the same with Musti.
"Sometimes when you make mistakes at big clubs you get punished. With Arsenal, people always seem to blame the defence for defeats. But I feel really safe behind them.
"They have experience and they are constantly talking through the whole game. When you play behind them, it's not like what people say. It's not, 'Oh, they make mistakes, they don't know how to play football'.
"I feel really safe, and now that we've kept three clean sheets on the bounce in the Premier League, people are starting to say that the defence is actually solid."