The Sunderland substitute who drew praise from Lee Johnson after staking his claim for a start against Accrington Stanley
It was telling that Lee Johnson made specific reference to the substitution in his post-match interview.
On an afternoon that delivered little in the way of tangible positives for the Black Cats, one undoubtedly came in the showing of substitute Jack Diamond.
Johnson was quick to hail his 'youthful exuberance' when he addressed the assembled media post-match, and his impact certainly lifted Sunderland after a disappointing start to the second half.
After their impressive first half showing - in which the hosts at times carved open their opponents at will - the performance after the interval was extremely anti-climatic.
Accrington were on top for large spells as the Black Cats struggled to get a foothold in the game, particularly after Colby Bishop netted just five minutes after the restart.
But the introduction of Diamond helped to turn the side somewhat, with his pace and direct nature helping to drive Sunderland forward.
He played a key role in the fifth goal of a dramatic afternoon as he broke forward following an Accrington corner, and matched his fine run with the correct decision as he threaded in Max Power - resisting other, earlier options.
Moments before that, he had shown excellent awareness to break in behind the backline and loft a strike over Toby Savin - only for it to drop just the wrong side of the far post.
Diamond's introduction undoubtedly lifted Sunderland and he has shown that he can affect games in recent weeks.
So with that in mind, could a start for the academy graduate help the Black Cats turn the tide?
There is an argument to be had that Diamond is better suited as an impact substitute - and his performance against Accrington perhaps only strengthened that particular train of thought.
But there is also a growing belief in some quarters that Sunderland need something different in the final third.
While it was defensive errors that proved costly against Stanley, Sunderland were also guilty of being wasteful of squandering some promising attacking positions and were struggling for an out ball when picked back during trickier stages of the second half.
In Diamond, they could have that – with his legs allowing the side to relieve some pressure and move the play up the field and away from their own box when coming under increasing pressure.
The youngster does, of course, face some real competition for starts in the wide areas.
Aiden McGeady’s impact has been profound while Lynden Gooch and Jordan Jones have both shown moments of promise in the last two games. There is also Chris Maguire to bring into the equation too.
But none of that quartet can quite bring the energy and ‘exuberance’, as Johnson puts it, that Diamond can.
That will be a useful weapon in the final weeks of the season, particularly against players who are physically and mentally tiring.
Whether Diamond’s impact will be greater from the start or from the bench remains to be seen – but if his performance against Accrington is anything to go by, he will have some form of impact in the final games.