Manchester City is a team that punishes any kind of mistake in your own half of the pitch and with Moreno returning from a semi-lengthy injury spell, it might not be wise to thrust him into the limelight just yet.
City come into the game still unbeaten in the league this season, and heavily linked with a move for Arsenal's Alexis Sanchez.
One of their biggest obstacles to doing so comes on Sunday, as they travel to Anfield to take on Liverpool.More news: White House: No deal reached yet on 'DACA'
Liverpool, meanwhile, find themselves on a run of four straight wins in all competitions, shooting down Swansea City, Leicester City and Burnley in the league before pipping Everton in the FA Cup third round last weekend.
Meanwhile, Mourinho is now preparing his team for their Premier League clash against Stoke City at Old Trafford on Monday night.
That task will have become a lot harder after wantaway Philippe Coutinho finally forced through his move to Barcelona.More news: Harrods to return statue of Dodi and Diana to Mohammed Al Fayed
Liverpool are 18 points below Manchester City and are looking to finish second in the league as there is very little chance of catching Guardiola's side given their rampant form since August.
Back in September, the Reds were ripped apart by the Citizens 5-0 at the Etihad Stadium but at Anfield, Klopp's men will hold stronger cards so it will be an intriguing battle.
How Jurgen Klopp spends the £142 million could make or break Liverpool's season - and given previous January transfer dealings, Reds supporters will hope any arrivals are more Luis Suarez than Andy Carroll.More news: Sanders Capital LLC Has Raised Stake in Taiwan Semiconductor Mfg LTD (TSM)
The player has impressed in Ukraine under Paulo Fonseca and also impressed when the side faced City in the Champions League.