'I thought it was the right step to go to England' - Marko Marin, July 2012.
Does he still think so? It's early days yet, but we wouldn't blame him for getting a little frustrated. Perhaps it's assumptive to say he's one player who may be glad to see the back of Di Matteo, but you could forgive him if he were.
After a bright pre-season, Marin suffered a hamstring injury which would cause him to miss the start of the season.
However he has been fit since late September, and played just 22 minutes of first team action in two months.
Those minutes came in the 6-0 League Cup win over Wolves on September 25, and since then he has featured on the bench seven times, but not been called upon once.
The German is a tricky winger who can play left or right, and is capable of turning matches with his skill and quick feet.
We wonder what he may have thought as he watched on last night, seeing defender Cesar Azpilicueta lining up in right midfield.
An on-form Marin would have been a far better bet in Turin. Given the circumstances though, it would not have been right to throw the German in, seeing as he has barely played for the club since arriving in the summer.
But it does beg questions over why Di Matteo chose not to integrate him with the first team as he would like; Had Marin been featuring in the Premier League, or even started the League Cup clash with Manchester United, he would have been a far more viable option.
Even 15 minutes against West Brom on Saturday, would have been useful in seeing if he could influence a tight match ahead of the crucial Champions League tie.
With the striking situation at Chelsea a mess at present, and Hazard being asked to go up top last night, it has meant an opening alongside Oscar and Mata in their supporting three.
Victor Moses, the matchwinner against Shakhtar, is another who may feel aggrieved at not starting last night, but Di Matteo clearly picked Azpilicueta to give the side a more defensive feel in the tough away game, as he did with Bertrand in the Champions League Final against Bayern.
OK, so it didn't work last night, but we can understand his reasoning. But we can't understand why he continued to limit his options in attack by refusing to give Marin a chance.
Marin remember was signed in May, before Di Matteo had been appointed as manager. He wasn't the Italian's choice. Could his lack of use have played a part in the gaffer's dismissal?
He played a week ago for Chelsea's under-21 side, as an overage player, and he scored and provided an assist, showing what he can do, a hint to his manager which was again ignored.
Chelsea now need a lift from somewhere going forward, to re-ignite their season, and it may just be Marin. Surely his chance can't be far away, but expect questions to grow over the German if he does not get one soon.
Is it time to give Marin an opportunity at Chelsea?
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