Gareth Southgate is considering switching formations for the European Championship, which could involve a return to three at the back due to worries over his side's defending.

England have used 4-3-3 throughout a qualifying campaign that finishes in Kosovo on Sunday, with the visitors already confirmed as group winners. But Southgate is not wedded to the system and will look at alternatives as he plans for next summer's tournament.

England successfully switched to 3-5-2 before the 2018 World Cup having played with a flat back four throughout qualifying — a system Southgate reverted to for the Nations League and Euro 2020 qualifying campaign in the belief it would bring the best out of his attacking players.

England boss Gareth Southgate is considering switching to three at the back for Euro 2020

That decision has been vindicated with 33 goals in seven qualifiers.

The manager is concerned about England's defensive solidity, however — with Harry Maguire the only centre back who is certain to be picked next summer — and is aiming to design a system that will mask those deficiencies.

Southgate's concerns about his defenders — brought about by costly errors made by John Stones and Michael Keane in recent matches and a poor record at set-pieces — have been magnified by the absence of a dominant midfielder in his squad.

John Stones is not a certain starter at Euro 2020 as Southgate is concerned with his defence

The 49-year-old praised the quality of midfielders available to England's European rivals ahead of Thursday's win over Montenegro, and is fearful his team could be exposed by top-quality opposition next summer.

His specific concerns include the belief Declan Rice has not kicked on since declaring for England over the Republic of Ireland towards the end of an outstanding breakthrough season at West Ham, and the apparent decline of Eric Dier and Dele Alli amid Tottenham's struggles this season.

Southgate used three at the back briefly after Joe Gomez came on (with Maguire and Stones) against Montenegro and his decision to switch to 3-5-2 before the World Cup followed lengthy talks with his coaching team.

A similar review is planned for the coming months.

After the Kosovo game, England do not play until two friendlies next March, with Southgate planning to use that time to find a system that minimises England's defensive frailties while allowing their attacking players to flourish.