Both the players were instrumental in the Red Devils’ 2-1 victory over Arsenal at the Emirates Stadium in the Premier League on Saturday.
While England international forward Rooney scored the all-important second goal with a delightful chip in the 85th minute, De Gea made a string of saves to keep the Gunners' attacker at bay until injury time when Olivier Giroud found the target.
Writing in his blog on Monday, Mata praised the two United stars, while also having positive words for teammate Antonio Valencia.
“Arsenal is a team that keeps attacking the entire game, even more when they play at home,” wrote the Spain international.
“They created good chances and it was tough, but we managed to bring the three points back to Manchester thanks to David’s great performance, Antonio’s shot that ended up in an own goal and Wayne’s clinical finish.
“We are fourth now and we want to keep climbing the table. After two victories in a row all we want now is to keep this good streak. It’s not going to be easy against Hull and Stoke, but we hope to play two good games and win.”
United are currently fourth in the Premier League table with 19 points from 12 matches.