When Manchester United's starting XI was revealed around an hour before kick-off, there was confusion about whether David Moyes had selected a 4‑5‑1 formation with Wayne Rooney up front and Danny Welbeck on the left, or a 4‑4‑1‑1 with Rooney behind Welbeck. In the end, United actually played a hybrid of the two systems, and Welbeck's positioning was the key to this tactical battle.

At kick-off Welbeck lined up in a wide position, but throughout the first 10 minutes – Bayern's weak period, judging by their sloppy starts against both Arsenal and United – he played up front, spearheading United's attack and harrying the Bayern centre-backs.

Welbeck soon had the ball in the net after some clever skill towards the opposite side of the pitch – the 'goal' was harshly disallowed for a high boot – and in that centre-right channel, he continued to cause Bayern problems.

There were three further incidents of Welbeck's pace in behind the Bayern defence providing a real threat. After 27 minutes he chased an over-hit long ball and was briefly pulled back by the Bayern centre-back Javi Martínez on the edge of the box. Welbeck made little of the incident, but Martínez was fortunate not to be penalised.

Then there was Welbeck's miss when put through on goal by Wayne Rooney for a one-on-one with Manuel Neuer – as clear a chance as United could possibly wish for. Welbeck's tame chip underlined his only major weakness, his finishing.

Finally, there was David de Gea's long goalkick downfield which an isolated Welbeck battled for, as Neuer darted out of his goal to sweep up – Welbeck was adjudged to have fouled Rafinha, again rather harshly. Bayern couldn't cope with his sheer speed.

The downside, however, was that when Welbeck was up front he wasn't on the left – and this meant the Bayern right-back Rafinha had acres of space to exploit. United's midfield shape was lopsided – Antonio Valencia was a pure right-winger but Ryan Giggs more of a left-sided central midfielder, and at 40 the Welshman doesn't possess the stamina to get out to the touchline and shut down Rafinha.

This might have been a deliberate ploy from United, however. In a hugely talented XI, Rafinha is arguably the only player who is not genuinely top-class – he's a fine footballer, but less threatening than any of Bayern's other attacking options. Perhaps Moyes was happy to allow him freedom.

Either way, Bayern continually hit huge diagonal balls out to Rafinha, who was galloping forward in typical Brazilian full-back fashion. He didn't have an obvious target for crosses, though; he continually looked up, saw only Thomas Müller in the box and decided to play short passes, often to Arjen Robben in an inside-right position, with the Dutchman shooting repeatedly with his left foot.

Nemanja Vidic's equaliser forced Pep Guardiola into action – he immediately summoned Mario Mandzukic, a classic No9. Perhaps, having gone ahead, United should have switched to the more defensive shape with Welbeck in a permanent left-sided position, to prevent Bayern advancing so easily. Instead, Welbeck remained up front, so Rafinha still had space, and more crucially he now had a target in the box, too.

Sure enough, a fine cross brought the equaliser: Rafinha received the ball in space and crossed for Mandzukic, who headed down for Bastian Schweinsteiger's excellent finish.United were fully aware of Bayern's threat by this point, but it appeared a calculated gamble to leave that wing open. Perhaps Welbeck should have moved left immediately after United went ahead.