The former Chelsea playmaker praised United's attacking intent, but was frustrated as Diego Costa's stoppage-time goal cancelled out Jesse Lingard's opener
"I want to highlight the team's image," Mata wrote on his blog on kicca.com
"From the first minute we went for the victory and played good football, but unfortunately we let slip two points in the last few moments
"It's a pity. It would have been a very important step in this second half of the Premiership, but Chelsea pushed hard (as expected) to at least tie the game and they finally scored their goal
"We are improving our game lately, and I'm sure this is the way to get a series of good results in the next few weeks
"The team is playing with more determination and confidence, and we want to keep it this way."
Mata, whose honours with Chelsea included the 2012 Champions League trophy, received a rousing ovation at Stamford Bridge
He added: "I'm deeply grateful for the reception from the Chelsea fans and their applause when I was substituted. It's something you keep in your memory forever."
Source: PA