Manchester United hope to discover the extent of Daley Blind’s knee injury on Tuesday as fears grow in Holland he may have torn medial ligaments.

Blind was injured in Holland’s 6-0 win over Latvia on Sunday and taken off in the first half. If scans show the midfielder has suffered a tear rather than tweaked the joint, the prognosis would be a recovery time of around six weeks, athough Blind’s father, Danny, is advising caution regarding the diagnosis.

For however long Blind is ruled out, his absence deepens United’s defensive problems as they prepare for Saturday’s trip to Arsenal. There are serious doubts already about David de Gea and Michael Carrick.

However De Gea, who dislocated a finger while on international duty with Spain, has not given up hope of being available to face Arsenal and the goalkeeper is waiting for United’s medical staff to rule on his fitness.

De Gea is definitely out of Spain’s friendly with Germany on Tuesday and, if he cannot play at the Emirates Stadium, Louis van Gaal will have to call on Anders Lindegaard, who nearly left United in the summer.

The manager will not be able to select Víctor Valdés, as the free agent is still recovering from a knee injury. The Spaniard has been training at the club as he continues rehabilitation from the anterior cruciate ligament he ruptured when playing for Barcelona against Celta Vigo in March. United have registered 24 players in their Premier League squad. They have space for one more over the age of 21 and could call on Valdés when fit.

If Lindegaard does take over in goal, it would be only a second Premier League start in two seasons. Ben Amos would provide back-up on the bench. Lindegaard played in the 4-0 win at Newcastle United on 5 April, his sole league appearance of last season.

With Carrick’s availability for the game at Arsenal also in the balance because of a groin injury, Van Gaal has to address gaps in defence because Phil Jones, Jonny Evans and Rafael da Silva may not be match-fit. Radamel Falcao could also struggle to start. Chris Smalling and Luke Shaw may play for England against Scotland and Van Gaal will hope the two defenders emerge unscathed.

Gerardo Martino, the Argentina manager, has agreed with Van Gaal that Ángel di María is suffering a dip in form. Di María is expected to feature in Argentina’s friendly with Portugal at Old Trafford on Tuesday night. The forward has failed to score since 5 October and was replaced in United’s previous outing, the 1-0 win over Crystal Palace.