Named among the substitutes last weekend, the duo impressed in the midweek EFL Cup win over Gillingham.
Son Heung-Ming (£7.4m) was rested on Wednesday and we expect him to be handed a third successive league start after eye-catching displays.
Both Janssen and Son warrant careful monitoring by FPL managers.
The Argentinian is poised to replace Kelechi Iheanacho (£7.1) up front in a 4-1-4-1 formation, although Pep Guardiola’s options on the flanks are somewhat restricted as Nolito (£9.0m) serves the second of a three-match suspension.
Raheem Sterling (£8.4m) has found his way into more than 233,000 new FPL squads ahead of Saturday's 11.30am deadline.
Daniel Sturridge (£10.0m) has started in back-to-back wins over Leicester City and Chelsea but is rated as doubtful for the Tigers encounter.
That could give Klopp the excuse to unleash a midfield trio of Sadio Mane (£9.0m), Roberto Firmino (£8.4m) and Philippe Coutinho (£8.1m) up front together for the first time since the Gameweek 3 draw at Tottenham Hotspur.
Much to the relief of his 151,000+ new owners, Romelu Lukaku (£9.3m) is expected to recover from the toe problem that forced him off during Everton's win over Middlesbrough.
The Toffees' top scorer has four goals and an assist in the last two Gameweeks ahead of a favourable trip to AFC Bournemouth.
Watford have worries on both flanks for the trip to Burnley.
Jose Holebas (£4.5m) is also a concern on the opposite side of midfield.
Juan Zuniga (£4.4m) offers an in-form alternative. He's been acquired by more than 33,000 FPL managers after emerging from the bench to grab a goal and assist in last week's win over Manchester United.
Burnley's Andre Gray (£6.4m) misses Monday's encounter as he begins a four-match suspension following a charge of misconduct.
Having scored two of his side's three goals, Defoe's availability looks vital as the Black Cats seek to profit from the absence of Scott Dann (£5.5m) in the Eagles' defence.