Tsimikas was among the 18 players called up from Jurgen Klopps senior squad for November, joining Greece for their friendly win over New Zealand.
But the left-back was not present for the 2-2 draw with France that rounded off his countrys Euro 2024 qualifiers, as one of many including suspended manager Gus Poyet absent.
It initially raised concerns over a new injury, with Andy Robertson already sidelined for the long term, but This Is Anfield learned his withdrawal was to avoid a yellow card that would rule him out of a playoff against Kazakhstan in March.
Speaking to the clubs official website, Tsimikas has since explained that it was his call to depart early, as he looks to train hard for Saturdays clash with Man City.
I decided to come back earlier to the team, to be with the squad, to train with the team, to be more ready, he said.
It was my decision and this is what I wanted to do because, as everybody knows, most of the time we play 12.30 after the international break and even the players who played far, they didnt come yet, they come probably one day, two days before the game.
So for me, I think it was a very good chance to come earlier to be with the team and to train hard.
Though Klopp has used Joe Gomez at left-back on occasion, Tsimikas is de facto first choice in the absence of Robertson, and therefore his fitness is hugely important.
The 27-year-old was widely criticised for a costly mistake in the 3-2 loss to Toulouse, but responded with two assists in the 3-0 victory over Brentford.
Signing off on a high was vital for Tsimikas, who will need to be at his best against Man City which he has acknowledged by returning to the AXA Training Centre early.
Before Brentford, I was not in the best condition of myself, he explained.
I try to find my best moments, I try to fight back, to be the player I was before, to make assists, to run, to defend, to do everything on the pitch.
Im really happy I came back against Brentford. I have to keep going with the same passion.
OK, this can happen, we play football, its a very difficult sport. Its up to me now to continue to play good and to make assists for the team.