Vitor Reis joined Abdukodir Khusanov and Omar Marmoush on Manchester City's shopping list this week, with the Blues chasing a triple deal that could top £120m.

Reports suggest City are moving closer to deals for centre-back Khusanov and forward Marmoush, with transfer fees in the process of being determined. Reis, another central defender, emerged as a fresh target this week and could join in January - even if Palmeiras apparently want to keep him until the summer and for the Club World Cup.

The three potential signings are seen as important parts of City's rebuild, although they will also be expected to help them out of their patchy run of form at present - especially Marmoush.

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City's small Premier League squad of just 21 players allows them to add up to four new additions this month, with their homegrown quota satisfied within the existing group. Theoretically, a fifth player could arrive as long as someone drops out - such as fringe left-back Josh Wilson-Esbrand.

Clubs can add players to their squads within transfer windows and must then submit their renewed squad list after the winter window shuts on February 3.

Things get a little more complicated in the Champions League, however, with City travelling to Paris Saint-Germain later this month before a final League Phase clash with Club Brugge at the Etihad in February.

Even if any new signings join before that Brugge game, or the PSG trip, they would not be eligible to play for City due to Champions League rules.

UEFA state that squads must be submitted before the League Phase begins and cannot be added to until the knockout stages. That means Marmoush, Khusanov, Reis or any other January signing would be unable to feature against PSG and Brugge even if they sign before either fixture.

In Marmoush's case, his involvement in the Europa League league phase wouldn't restrict him from being registered with City in the Champions League knockouts, and neither would Khusanov's appearances in Conference League qualifying.

Once City have booked a place in the knockout stages - including any play-off to reach the last-16 - they can add up to three new players to their UEFA squad. So in the event of any signings above three new additions, City would have to decide which player would be left out in the Champions League.

There is another possible issue in the Champions League, however. The rules are a little more restrictive with a difference between 'club-trained' players and 'association-trained' players within their homegrown allowance. Of the maximum 25 players, eight places are reserved for homegrown players. City have eight who satisfy that description in their squad of 22, but only a maximum of four of those spots can be taken up by players who weren't trained at City.

And the Blues have five of those 'association-trained' players, so one cannot be included, restricting the squad to a maximum of 24.

As City can only use seven of their eight homegrown spots, that could leave just two more places for new signings - which could leave another decision of leaving out a new addition if more than two arrive.