By Mitch Phillips

MARSEILLE, France (Reuters) - England and Russia are the big beasts of Group B and, though each would love a winning start when they meet on Saturday, the fear of losing could well become all-pervading and lead to a cagey encounter.

With games against Wales and Slovakia to come, and the potential for three teams to qualify with two guaranteed, a point at the Velodrome might look a very useful result in a couple of weeks.

England, on the back of winning all 10 qualifiers, not to mention a rare victory in Germany in a friendly, start favorites and will expect to make the running in front of a 60,000 crowd that will be predominantly behind them.

However, despite that great run of form, England are anything but a settled side as Roy Hodgson struggles with the question of how to shoe-horn his form players into an established system.

Strikers Jamie Vardy, fresh from leading Leicester City to the most unlikely Premier League title, and Harry Kane, the Premier League's top scorer, seemingly demand selection.

But Hodgson is adamant Wayne Rooney, the captain and most experienced squad member, should get a starting berth, leaving the coach experimenting with his attacking options right up to the last minute.

At least he is picking from strength in that regard as his, and England's more pressing concern is in central defense where any combination of Gary Cahill, Chris Smalling and John Stones has looked vulnerable and remains England's Achilles heel.

IMPRESSIVE STATISTICS

England have not lost in 90 or 120 minutes in 22 Euro matches in finals and qualifiers, going back to a 3-2 defeat by Croatia in November 2007.

The impressive statistics are skewed, however, as they lost on penalties to Italy in the 2012 quarter-finals and failed to qualify in 2008.

Russia reached the semi-finals that year with a side full of passion and pace but they were disappointing in 2012 and in the 2014 World Cup and the current crop are not a group to have fans on the edge of their seats.

They are, however, a well-organized and technically adept squad and coach Leonid Slutsky has quickly developed a strong team spirit since taking over from Fabio Capello last August.

He has, however, been forced to change his plans somewhat after injuries ruled midfielders Alan Dzagoev and, after last week's 1-1 draw with Serbia, Igor Denisov out of the tournament.

With that to deal with and winnable games on the horizon, Russia are unlikely to take too many risks on Saturday, leaving it up to England to decide whether to open up in all-out pursuit of victory or indulge in 90 minutes of cautious chess.

(Editing by Ken Ferris)