With price hikes applied across their squad in 2016/17, most notably to Vardy and Mahrez, they have struggled to justfiy their new valuations.
Vardy has claimed only two goals from eight starts, and the underlying statistics in the table below confirm he is struggling in 2016/17.
His goal attempts are halved from 3.2 per match, while penalty-area attempts are down to 1.3 a match from last season's 2.7.
Vardy's shot accuracy is also well below that of his 24-goal campaign (28.6% v 45.2%), meaning there is little evidence to suggest he presents a viable FPL option.
Jamie Vardy's match averages
|Penalty area goal attempts||2.7||1.3|
Mahrez's statistics offer more encouragement, however.
Despite failing to find the net from open play in 2016/17, the Algerian's goal attempts and penalty-area attempts both show a marginal increase at 2.4 and 1.4 per match, compared with last season's 2.3 and 1.3.
But having provided 11 assists last term, it is notable Mahrez is creating chances at a slower rate this season, down to 1.1 per match from 1.8.
Riyad Mahrez's per match averages
|Penalty area goal attempts||1.3||1.4|
That can perhaps be explained by Leicester's stuttering start to their title defence.
Team selection and performances appear to have been affected by their UEFA Champions League campaign. But having boosted their chances of progression from the group stages with three successive victories, it is expected Ranieri's side will place more importance on addressing their Premier League form.
That shift will coincide with a run of fixtures that could give them a platform to climb the table from their present position of 12th.
Following this weekend's testing trip to Tottenham Hotspur, Leicester entertain West Bromwich Albion and Middlesbrough at the King Power Stadium.
Visits to Watford and Sunderland offer further promising scenarios, according to the Fixture Difficulty Ranking (FDR).
Having claimed three clean sheets in five home matches, conceding only two goals, FPL managers should be aware of the promise presented by the defence and, in particular, Christian Fuchs (£5.4m).
The Austrian earned his first Premier League goal in the Gameweek 9 victory over Crystal Palace and, having provided four assists with 25 bonus points last season, remains the prize asset in Ranieri's back line as Leicester's top FPL points scorer this season.
In attacking terms, the options extend beyond Vardy and Mahrez, as Islam Slimani (£8.5m) presents a new candidate to consider.
With two goals and an assist from five Premier League starts, Slimani could spearhead the Leicester attack.