The defender missed United's first two games of the season with a knee injury.

And manager Jose Mourinho is not prepared to risk the 33-year-old in Wednesday's Group H game in Bern.

"We decided not to bring Valencia because his knee is not a knee that needs an artificial pitch," he said.

The Portuguese also confirmed that left-back Luke Shaw would play in the game after missing United's 2-1 Premier League win at Watford at the weekend.

Mourinho draws on Federer for inspiration

Roger Federer has won 11 Grand Slam titles on a hard court surface

Despite his reluctance to use Valencia in Wednesday's game, Mourinho says the artificial surface will act as no excuse should United fail to win, referencing Swiss tennis player Roger Federer in his reasoning.

"I don't want to use that, especially before the match, as a possible excuse for a not good performance," added Mourinho.

"I can get an example, since we are in Switzerland, the home of one of the best ever tennis players - I'm pretty sure that the big man sometimes is not happy to play on such a surface but he has to play and he has to win.

"Everybody knows he has a favourite surface, but he also has to win on other surfaces that he is not in love with, so we have to do it."

Last season, United reached the last 16 of the Champions League before losing 2-1 over two legs to Spanish side Sevilla.

As well as Young Boys, they will face Valencia of Spain and Juventus, setting up a possible reunion with former United star Cristiano Ronaldo, who joined the Italian side from Champions League holders Real Madrid this summer.

Juve the team to beat in Group H - Man United's chances of progressing

Simon Gleave, head of sports analysis at Gracenote:

"Manchester United's chances of progress to the last 16 of this season's Champions League declined slightly after being paired with Juventus, who are ranked fourth in Europe by the Euro Club Index, when there was a chance of drawing the much weaker Lokomotiv Moscow.

"Manchester United are rated the 12th best team in Europe (11th best in the Champions League in Chelsea's absence). Valencia (22nd) and Switzerland's Young Boys (55th) complete United's Group H opponents."

Switzerland an unhappy European destination for United

• This will be Young Boys' first European Cup/Champions League campaign since 1986-87, and their first since the competition was rebranded in 1992.
• This is Manchester United's 22nd Champions League participation, the most for an English side and the joint-fourth most after Real Madrid, Barcelona and Porto (23).
• Young Boys will be hosting an English team in major European competition for the first time since February 2015, when they faced Everton in the last 32 of the Europa League - the Swiss champions lost 4-1 that day and were beaten 3-1 in the return leg.
• United's former Everton striker Romelu Lukaku claimed a hat-trick at the Stade de Suisse before scoring twice at Goodison Park.
• Young Boys have won just one of their previous six matches against English sides (D1 L4), a 3-2 home win over Tottenham in the first leg of their Champions League play-off in 2010-11. Spurs won the return leg 4-0.
• United have only ever faced one side from Switzerland in European competition - FC Basel. They have won two, drawn two and lost two of their previous six encounters.
• United have lost on their last two trips to Switzerland in the Champions League, 2-1 in December 2011 and 1-0 in November 2017, both to FC Basel.
• Despite being eliminated in the second leg at the Santiago Bernabeu, Young Boys' last home game in the European Cup/Champions League was a victory against Real Madrid in a first-round tie (1-0 in September 1986).
• United have won just three of their last 14 away games in the Champions League (D5 L6) and have scored just one goal in their last three such matches (W1 D1 L1).