When Manchester United scored two late goals on Sunday to secure a come-from-behind 3-2 victory over Aston Villa, the result seemed to sweep under the rug the idea that United were a team in serious danger of relinquishing their Premier League lead heading into the home stretch.

After Tuesday’s 2-2 draw at home to FC Porto in the Champions League, however, the argument that United appears to be running out of gas at a very crucial point in time quickly regained a lot of its validity.

If the Stretford End’s reaction to Federico Macheda’s winner at Old Trafford on Sunday was any indication, United’s win over fellow recent strugglers Villa was just what the red-clad doctor had ordered. In his team’s previous two games, manager Sir Alex Ferguson had watched his side get out-everythinged at home against arch-rival Liverpool in a 4-1 shellacking before losing again, 2-0 at Fulham. Ferguson needed to stop the bleeding, and Macheda’s wonder goal in injury time seemed to do the trick.

At least, that is, for a few days.

Seemingly buoyed by Macheda’s instant rise to fame over the weekend, United had to feel they were heavy favorites coming into their Champions League quarterfinal tie with FC Porto, but it appears the Portuguese side never got that memo.

A calamitous defensive mistake by Jonny Evans allowed Cristian Rodriguez to give Porto the lead on five minutes, and even though goals from Wayne Rooney – another goal that can largely be attributed to comedy defending – and Carlos Tevez would later overturn the early deficit, substitute Mariano leveled the score in the 90th minute to give Os Dragões a vital pair of away goals heading into the second leg at the Estádio do Dragão, a venue at which no English club side has ever won.

“If you have a 2-1 lead with five minutes to go, you really should be seeing the game out,” Ferguson told ITV Sport after the match. It is a slightly peculiar thing to say, given that United had just stolen a win in their domestic league 48 hours earlier, but he certainly wasn’t wrong in his assessment here. A score draw at the end of the night’s proceedings flattered United, and, given recent performances, it’s likely that only an outright victory in Portugal will be enough for Ferguson’s side to advance to the semifinals.

First thing’s first, though, and United will need to put in a much better showing on Saturday away to Sunderland, if only to really prove that they’ve regained their bearings in the league. On paper, their visit to the Stadium of Light ought to be a cakewalk, with the Black Cats only three points above the drop. Sunderland almost stole a point in December at Old Trafford were it not for a late winner from Nemanja Vidic, though, so United will want to be careful in the return trip.

Beyond that, I’m not really sure that I can see United pulling off the much-hyped quintuple – not unless they get some help from results elsewhere. They will have it all to do in the second leg of their Champions League tie in Porto, and any advancement there and in the FA Cup would mean that fixtures would be coming even faster and more furious for United than they’re already set to become.

“Are you watching, Merseyside?” seemed to be the chant emanating from the Old Trafford faithful on Sunday afternoon, but it will be those same fans who should be scoreboard-watching the rest of the way. The possibility of a five-trophy haul for the season is still there, but even if United can somehow find a way past Porto, they may still need to rely on a slip-up or two from their hated rivals on the south border of Stanley Park along the way.