Supporters and journalists alike were surprised when news broke of the Reds interest in the Japan international.
Therefore, the former Stuttgart midfielder was viewed as a panic buy, with many observers questioning the decision to sign a significantly older player who didn't fit the club's usual recruitment policy.
However, the 54-cap international insists that he can silence the doubters with his performances.
"I understand they say that, I am 30-years-old and Liverpool wanted to sign younger players, that is normal right.
I didn't care what they said, I just have to do my job. If I play well then they will say good signing.
Today, my performance, not just today, is getting better and better, I can still improve more, so I just keep it going and try to do my job every game."
The competition for places in Liverpool's midfield is a tough one, but the 30-year-old is happy to play his part and was very complimentary of his colleagues in Jurgen Klopp's engine room.
"I think we have very good midfielders, not only the four new players, we have Curtis, Harvey, so many number eights.
Yeah, we have sixes, Macca and I, of course, Thiago is injured, but he comes back and Stefan is also a six.
Macca is more offensive, defensively he always try to make it better, if he keeps playing, he gets very strong defensively.
I can learn a lot from him and I think it is a very good balance between me and Macca."
When asked about the Reds' attack, who have accounted for 25 goals out of their 33 scored in 13 matches so far this season, the midfielder waxed lyrical.
"That is normal for Liverpool, no?
We have very good attackers, everyone works, you know, 100% every game, even if we start or not, from the bench today, Mo scores.
It is very important to win the game, we don't play only the first 11 right? It is important that everyone is always ready to play."
Adapting to the Premier League
The veteran admitted that he has not featured enough in the Premier League to gauge the difference in intensity between the domestic and European game.
"I didn't play too many games in the Premier League, so I don't see the difference much.
Against Newcastle, it was really tough game physically, the speed, everything is different from the Europa League.
Bundesliga is more defensive, most of the teams try to make blocks and try to play football, here in Premier League, we always try to play it forward, to the goal, so that is the main thing.
Physically, every team [in the Premier League] has amazing players.
"Training is totally different between Liverpool and Stuttgart, I was surprised to train here because they had a lot of quality and it is very intense, but that is what I wanted."
The former Stuttgart man scored his first Reds goal in the 5-1 demolition of Toulouse, and he gave an insight into his emotions on the special night in front of a home crowd, and also on the squad's ambitions for this season to LFCTV.
"It was amazing when I scored.
Especially at Anfield. Amazing experience.
I just try my best every game. Everyone always tries to help me so I feel very comfortable with this crowd.
It is great to win, it was not an easy game, in the Europa League, I'm just happy to win.
I don't feel pressure, I feel comfortable playing home games, I just try to enjoy every match.