It is a critical international break for several Chelsea men, with a last chance to qualify for next summer's European Championships.

Our Czech and Portuguese international players all have vital play-off ties to conclude over the next week, with aggregate victory required to book the final places in Ukraine and Poland.

Petr Cech, the Czech player of the year, will be hoping for clean sheets against Montenegro, who finished second in England's group. The Czechs will play at home in Prague in the first leg on Friday, before the return game in Podgorica next Tuesday.

Portugal midfielder Raul Meireles meets Bosnia and Herzegovina in a repeat of their play-off for the 2010 World Cup, the first leg taking place in Zenica before the return in Lisbon four days later. The Portuguese were victorious two years ago, winning both legs 1-0. Jose Bosingwa is not in their squad for the rematch.

Elsewhere there are numerous friendlies to keep many of the rest of the Chelsea squad occupied.

England and Spain squads include a combined six Blues - John Terry, Frank Lampard, Ashley Cole and new inclusion Daniel Sturridge, and Fernando Torres and Juan Mata. England play Spain on Saturday and Sweden on Tuesday, both at Wembley, with Spain moving on to play an away game to Costa Rica.

David Luiz is the sole Brazilian called up from Chelsea for friendly fixtures. He travels for an away game against Gabon, to take place in African nation's capital city Libreville on Thursday, before they meet Egypt in Doha on Monday.

Salomon Kalou is with Ivory Coast as they travel to Cape Town to play South Africa on Saturday, then meeting Senegal in Paris on Tuesday. Didier Drogbahas been withdrawn from the squad following the removal of a metal plate in his arm.

John Mikel Obi will join up with Nigeria for their home friendlies against Botswana on Saturday and Zambia on Tuesday. Both games are in Abuja, and the Super Eagles will want to impress having failed to qualify for January's Africa Cup of Nations.

Back in Europe, Branislav Ivanovic, whose Serbia failed in their European qualification bid, finishing third behind Italy and Estonia, travels to Mexico for Friday's friendly before heading to Honduras on Monday.

Frenchman Florent Malouda, safely through, will come up against BelgianRomelu Lukaku in Paris on Tuesday. Before that the French meet USA on Friday, while the Belgians host Romania in Liege.

On-loan Jeffrey Bruma will miss Holland's friendlies against Switzerland and Germany due to a muscle injury.

Among the players possibly in action at Under 21 level, Josh McEachran has a double-header with England, entertaining Iceland at Colchester on Thursday before travelling to Belgium on Monday, while Oriol Romeu has two home qualifiers for Spain, meeting Estonia in Melilla on Thursday and Switzerland in Cordoba on Monday.

Slovakian Milan Lalkovic is in the squad that meets France Under 21s in Angers on Monday, Gael Kakuta is in the France squad, while Conor Clifford is with the Irish group that hosts Liechtenstein on Monday. Both games are European Championship qualifiers.

At Under 19 level, English pair Nathaniel Chalobah and Todd Kane will be in Brighton to play Denmark in a friendly on Thursday.

Some young Chelsea players have already been in action for Under 17 and Under 16 international age groups in the last fortnight.

England Under 17s won three games out of three in a European championship qualification tournament held in Bosnia - Lewis Baker, John Swift, Fankaty Dabo and Jordan Houghton playing their part in wins over Holland, Bosnia and Herzegovina and Latvia. Chelsea youth team defender Nathan Ake played for Holland.

England Under 16s beat Wales 4-0 with two Chelsea schoolboys who are regulars in our youth team this season, Ruben Loftus-Cheek and Alex Kiwomya, grabbing a goal each. Loftus-Cheek was captain.