Speculation is rife that Everton will make a big-money move for the 28-year-old, whose future at Manchester United seems bleek following the arrival of Jose Mourinho, who sold him to the Red Devils during his time as Chelsea manager.
The Telegraph reported on Sunday that Toffees boss Ronald Koeman is trying desperately to convince the Spain international to join the Merseyside outfit.
He arguably plays his best football in a number 10 role and, should a move materialise, it may have an impact on 22-year-old attacker Barkley, who operates in a similar position.
Consequently, Liverpool legend Nicol believes that complications could arise if they were to indeed sign the former Valencia star, adding that he prefers the young England international to his Spanish counterpart.
"If I'm Barkley I'm wondering whether I'm going to start, because if Juan Mata goes to Everton he's starting" he told ESPN.
"It's a big season for him [Barkley]. He needs to prove he's going to be a player who can play at a high level for seasons to come, so I'd go with him."
It is indeed a big season for Barkley, who enjoyed a decent 2015-16 campaign but never really showed the kind of form he is capable of on a regular basis - but who did at Everton last season? With the exception of Stones, the candidates then dwindle.