Swansea City are the visitors to Stamford Bridge in Thursday's traditional Boxing Day fixtures.
Michu, 27, has scored 28 goals for the Swans since signing from Rayo Vallecano in the close season in 2012 but has been hampered all this season by ankle and knee problems.
It is a first ever international call up for Michu, who has scored five times for Swansea this season following an incredible debut campaign in the Premier League with 22 goals last season.
A Swansea side coached by former Real Madrid and Barcelona star Michael Laudrup and featuring six Spaniards, including captain Angel Rangel, punished opponents who played 80 minutes with 10 men to run out thoroughly deserving winners.
Shelvey, a former Liverpool player, was involved in all four goals during the 2-2 draw at the Liberty Stadium.
In other matches late on Thursday, Real Betis triumphed 2-1 at Czechs Jablonec and Ukraine giants Dynamo Kiev won 3-2 at Kazakhs Aktobe Lento.
Pellegrini, meanwhile, has already admitted having a verbal agreement with City to take over for next season. Navas was believed to be one of his main transfer targets as he tries to rejuvenate the 2011/12 English champions after a disappointing campaign in which they finished without a major trophy.
Cech believes the pressure will continue to mount until the very end of the campaign and Chelsea cannot afford any slip-ups against a Swansea side that beat them in the last four of the League cup earlier this season.
Suarez is followed by Van Persie, Gareth Bale, Michu, Demba Ba, Christian Benteke, Rickie Lambert, Dimitar Berbatov, Romelu Lukaku and Santi Cazorla to round off the top-10.
Goals from Nathan Dyer and Michu gave Swansea a 2-0 half-time lead, with Dyer doubling his tally early in the second half before Jonathan de Guzman added a fourth with a penalty after Bradford goalkeeper Matt Duke was sent off.
Michu, who has been one of the revelations of the season, got the home side off to the best possible start when he finished from close range after QPR's Brazilian 'keeper Julio Cesar had spilled Nathan Dyer's shot.
His displays had prompted speculation he could be set for a lucrative move away from the south Wales club, but he has now committed himself to the Liberty Stadium until 2016.
Chelsea did their best work in the middle third, where Hazard in particular continued to cause Swansea a headache with his prodigious movement. Yet for all Chelsea's quality, it was Swansea who looked the more comfortable.
Laudrup only took over at Swansea seven months ago but he says the reactions of the people around him have left him in no doubt as to the magnitude of Wednesday's match.
Wednesday's result was the second surprise English League Cup semi-final first leg scoreline in as many days, if not as great an upset as fourth-tier Bradford City's 3-1 defeat of Premier League Aston Villa on Tuesday.
Victory moved Swansea, who face Chelsea in the return leg at their Liberty Stadium home on January 23, closer to a first major cup final appearance.
Chelsea boss Rafael Benitez brought Frank Lampard and Demba Ba off the bench in search of an equaliser but none came.
Manchester United were prevented from restoring their six-point lead over Manchester City at the top of the Premier League after being held to a 1-1 draw at Swansea City on Sunday.