The Spain international posts weekly on his blog, often discussing recent matches but this week he titled his latest page: ‘Not the time for posts’.
Mata was an unused substitute on Saturday when Jose Mourinho’s side fought back from 2-0 down at St Mary’s to draw the match.
The Manchester United midfielder wrote on the post: ‘Unfortunately, I feel as though it isn’t the time for posts.
‘I imagine, and understand completely, that you will not want to read words that, although honest, won’t be of much comfort to you.
‘Therefore, I am only going to publish this to thank you all, as ever, for your support. Thanks a lot.’
The 30-year-old has started six of United’s 14 Premier League matches this season and only one Champions League match.
Mourinho sold Mata to Manchester United when he was the Chelsea manager in 2014.
The Red Devils boss is now under pressure and the favourite to be the next Premier League manager to be sacked as United linger in 7th – 16 points behind leaders Manchester City.