Tuchel was sacked by Chelsea on Wednesday morning just hours after the Blues had been humbled by Croatian side Dinamo Zagreb in the Champions League.
The German’s sacking also came just three months after Chelsea’s new owners, Todd Boehly and Clearlake Capital, completed their £4.25billion takeover at Stamford Bridge.
Tuchel had been backed heavily in the transfer market, to the tune of a record world-record £273million this summer, but he was axed having made a disappointing start to the season and with Chelsea currently sat sixth in the Premier League.
And asked if he was surprised, Arteta said: “I was yes. It was right before training when we got the news.
“It is always sad for any colleague in this profession to get fired. Unfortunately we know how this works. Wish him the best of luck.
“It makes me realise that we have a profession that, in a big percent this is going to happen.
“We have to prepare for it and we have to enjoy the journey and we have to enjoy every day because you never know what’s coming.”