Until Saturday's morale-boosting 1-0 win at Crystal Palace, West Ham have been found wanting so far this season.
And the same can be said for Calleri, who has missed a string of sitters which have cost Slaven Bilic's side dear in several games.
His form, or lack of it, has seen him drop out of contention in recent weeks and he also suffered an injury which has kept him on the sidelines.
Calleri during training
The 23-year-old has admitted the language barrier and style of play in England has held him back so far.
But there was a boost for Bilic, the player and fans this week when a video from the club's pre-Sunderland training showed he may finally have found his shooting boots.
Calleri with manager Slaven Bilic after being substituted
The clip, posted on West Ham's official Twitter account, shows Calleri nonchalantly lobbing the goalkeeper with a sublime finish from less than eight yards out much to the delight of his watching teammates.
"Cheeky from Jonathan Calleri," West Ham posted on Twitter.
While the player has looked leggy and has been missing that killer touch in front of goal, some fans would argue at least the player has been getting himself into the positions to score.
Is Calleri looking sharper?
But his profligacy when he has the ball in those positions has not helped the settling in process.
Perhaps the break Calleri has had will have given him the chance to acclimatise to his new surroundings and get up to the required speed to succeed in the Premier League.