Manchester United defender Chris Smalling has described the prospect of a third straight defeat as “unacceptable."
United enjoyed a flying start to the campaign under Jose Mourinho, as they won the Community Shield and their first three Premier League matches.
That positive run came to an end with the 2-1 home defeat to rivals Manchester City on Saturday, followed by a 1-0 loss away to Feyenoord in the Europa League on Thursday night.
A bad night almost got worse for United - Smalling almost missed the plane home after struggling to produce a urine sample for doping control.
United travel to Watford on Sunday and Smalling, who captained the side in the Netherlands, said of the quick turnaround: "I think if anything, that's a good thing. We don't have time to dwell and we have a few days to recover.
"We [need to] make sure that we stand up and be counted on Sunday because we've got a big result to get.
"I think [the confidence] does take a little knock, but I think we can't forget some of the chances we created.
"I think on Sunday character needs to shine through because it's unacceptable to lose three games in a row."
United looked laboured in their defeat to Feyenoord at De Kuip, but the England international is convinced they can still advance to the knockout stages of the competition.
"I think we came into this game very confident and we thought we'd get a good result," Smalling told MUTV.
"We wanted to give ourselves a good start to the group but unfortunately we didn't play up to our usual standards.
"They didn't create too many chances but we didn't do enough either to win the game. I think our urgency was there in the second half but we needed to have that in the first half as well.
"I think the defeat puts pressure on the second game but we do have five games to make sure we finish top of the group."