While Swansea are missing him badly, their Monday Night Football opponents Everton are still waiting for the real Gylfi Sigurdsson to emerge. Adam Bate examines the impact of his absence at his old club and why his new one have not yet seen the best from him."It is a big club," said Sam Allardyce when quizzed on Gylfi Sigurdsson's slow start to life at Everton following his £45m move in August. "No disrespect to Swansea," he added, "[but] you are playing sbo on a bigger stage so you have to have a greater mentality to come out and produce because the demand is higher to play for Everton."Gylfi came so late because of the ongoing saga of 'How much will he be and will Swansea let him go? Will they or won't they?' In that time he was not really training with the first team and it wasn't happening for him in terms of a full pre-season. So he is on catch-up."Sigurdsson has still had his moments. There was his outrageous strike against Hajduk Split in August and, more recently, he got the opening goal of Allardyce's reign in the win over Huddersfield. Even so, things have not gone as smoothly as hoped for player or club. And yet, those travails are nothing compared to the struggles of Sigurdsson's old club Swansea.Monday's visitors to Goodison Park arrive as the Premier League's bottom club and it is acutely apparent how badly that last season's player sbo of the year has been missed. Swansea are the lowest scorers in the Premier League with just nine goals. To put that into some sort of context, Sigurdsson alone had five goals and five assists at this stage of last season.Given that Swansea have a better defensive record than more than half of the teams in the league, the problem is clear. Renato Sanches, ostensibly signed as Sigurdsson's replacement on deadline day, has found the advertising hoardings more times than the net and has not provided a single assist either. Jordan Ayew has not scored in his 13 starts since August.