Javier Hernández was the bargain buy of last season but this week his value to Manchester United could be demonstrated by the costliness of his absence. The ankle ligament damage that the Mexican suffered at Villa Park could keep him out of action for up to a month.

It will certainly prevent him from playing at Basel on Wednesday, when failure to secure at least a point would mean United failing to reach the Champions League knock-out stages for the first time since 2006. A 0-0 stalemate would suffice in Switzerland but Basel showed in the 3-3 draw at Old Trafford in September that they are a dangerous attacking force so it is likely that United will need to score. Hence Hernández's absence could be crucial.

Since their jittery 2-0 home win over Norwich on October 1 United have scored seven goals in seven Premier League games. Hernández scored four of those. And yet, after hailing his decisive contribution to last season's title triumph, some United fans have been questioning the Mexican's worth, suggesting he is not a rounded enough player to become an enduring success at Old Trafford.

Sir Alex Ferguson obviously believes otherwise, which is why the 23-year-old was given a new five-year contract in October, and the way United have been playing recently has heightened his importance. Ferguson has accentuated defence in recent weeks in response to earlier erraticness in that department, detracting from United's attacking lustre.

Creating fewer chances makes taking them vital and Hernández, whose start to the campaign was delayed by injury, has tended to do that. Last season he had the third-best shots-to-goal ratio in the Premier League (29.55%); this term he has been even deadlier, increasing his ratio to 35.29%.

Wayne Rooney started the season in devastating form, with nine goals in his first five games, but his only goals in 10 matches since then came against the Romanian minnows Otelul Galati. With Dimitar Berbatov and Michael Owen injured, and Danny Welbeck still working his way back after suffering a muscle injury on England duty last month, United have developed a certain dependency on Hernández.

Rooney had chances to score at Villa Park but, other than the shot he blazed over the bar from 15 yards in the 87th minute after a slick one-two with Michael Carrick, they were all from outside the area. Although he did not play as deep as he did against Everton and Swansea City in recent months, when he was effectively a midfielder, the England striker was still seldom near goal, meaning that several crosses against Villa, notably from Nani, were left to fly across the six-yard box without any United player threatening to get on the end of them. On the one occasion after Hernández's departure in the 11th minute that a United player did get into the sort of position that the Mexican usually inhabits, they scored the only goal of the game, Phil Jones, of all people, claiming the first goal of his career.

It is not hard to understand why Rooney feels the need to drop so deep – United have often lacked creativity in central midfield since Tom Cleverley got injured – but against Villa Carrick played well and ensured a regular supply of balls to the wide men, so Rooney could have ventured further forward to receive the wingers' crosses. Perhaps he sat deep in anticipation of the trip to Basel, when United will also be without the suspended Carrick.

Whatever their problems, United are in a better state than Villa. This was another abject performance by Alex McLeish's team. They seemed zombified during a first half in which they failed to muster a shot and in the second half they threatened only when the substitute Emile Heskey or their centre-backs rumbled into the United box to get on the end of hopeful hoofs. Neither the result nor the style impressed Villa fans. Ashley Young had a largely ineffective game for United but his presence was still a reminder that Villa used to play with adventure and menace.

Young's replacement, Charles N'Zogbia, was not in Villa's squad, having been excluded as punishment for failing to show up for an appointment with the club physiotherapist last Wednesday. The £9.5m summer recruit from Wigan was one of the players McLeish had banked on to bring a little creativity to Villa but he has been a flop so far. McLeish, however, believes the Frenchman could still come good. "The players know we have club rules and he has to adhere to them but there are no grudges," said McLeish. "I just want to see Charles go to another level. He's got to be receptive and realise that I want to help himbecause we need all the help we can get."

Man of the match Phil Jones (Manchester United)