When Iago Aspas came on for Coutinho away to Swansea City on Monday something changed.
Liverpool became less of a threat in attack, handing the initiative to Swansea despite Aspas' fresh pair of legs.
It told us two things, on - how important Coutinho is to the side, and secondly - Aspas is still to find his feet in English football.
The 26-year-old signing from Celta Vigo had started the Reds previous three games, helping their rise to the top of the table and seeing them win each one.
However he had generally failed to standout, and is yet to net - leading to Brendan Rodgers demoting him to the bench.
Now with Luis Suarez back and Luis Alberto bagging a hat-trick for Liverpool's under-21 side, competition for places is increasing and Aspas may be a little worried about his place.
The question is whether fans should be worried about him. Aspas is already attracting criticism from some sections of support, worried that the club have signed 'another Borini'.
However English football is littered with examples of foreign players who have taken time to adjust before hitting form, just look at Olivier Giroud at Arsenal - this time last season he was being dubbed the new Chamakh, now his goalscoring ratio is being compared to the club's recent greats.
Aspas was handed Liverpool's famous number nine shirt for a reason - that manager Brendan Rodgers has real faith in him.
Liverpool have an interesting Capital One Cup match-up next week at Old Trafford against Manchester United, and it will be a game where the dynamic of the team will change as players are rotated in and out, and Luis Suarez makes his long-awaited return.
Could it be this becomes the night when Aspas shows what he is all about, and becomes a hero by dumping United out of the cup?
Liverpool fans what are your early thoughts on Aspas?
image: © grodal