Manchester United boss Jose Mourinho is facing up to having to eat humble pie after Chris Smalling was ruled out of action for up to a month with a broken toe.

The Portuguese manager openly questioned Smalling's fight for the cause following the defender's decision not to step up to the plate and feature in the 3-1 victory over Swansea City last Sunday.

However, Daily Mail reported that Smalling is now set for a spell on the sidelines, with rumours circulating that the 26-year-old could be unavailable for four weeks after he suffered a fractured toe - a prognosis that is sure to leave Mourinho feeling extremely embarrassed over his reccent comments.

Smalling could now be due to miss up to seven crunch matches for the Red Devils in the lead up to the Christmas fixture schedule, including crucial Premier League encounters with Arsenal and Tottenham Hotspur, as well as the League Cup quarter-final tie with West Ham United.

The news will come as a double whammy to Mourinho, with his ill-judged criticism of Smalling - and United team mate Luke Shaw - now added to by one of his key defenders being forced to spend time on the treatment table instead of on the pitch.

Smalling had already supposedly taken two injections in his foot to participate in United's 4-0 defeat to Chelsea in October, but that did not prevent the England international bearing the brunt of an attack from Mourinho in the wake of the Red Devils' win over Swansea.

Mourinho had blasted Smalling, 26, and 21-year-old full-back Shaw over their desire to play through the pain barrier at the Liberty Stadium, and remarked that his stars had a "problem" with playing for the club when feeling discomfort over a possible injury.

On Sunday he said: “I have a friend who is a big tennis player and he tells me when he remembered more the times he plays with pain than the times he plays without pain. To compete you have to go to the limit. It is cultural for some – and that is not my culture. More than me, it is Man United.

“We have players with ‘problems’. At every sport – and I know because I have friends in others sports and they play at the highest level in their sport, and how many times they play when you are not 100 per cent.”

The ex-Chelsea boss is already without fellow centre back Eric Bailly for another month due to a knee ligament injury and, whilst Phil Jones returned to first team action against Swansea to bolster Mourinho's defensive options.

The 53-year-old will be left sweating over the possibility of another one of his defenders pulling up with a knock or strain.

Marcos Rojo and Daley Blind are also notable options available to Mourinho in the heart of United's defence, while veteran midfielder Michael Carrick has been deployed as an emergency defender in the past couple of seasons by Mourinho's predecessor Louis Van Gaal.