Juan Mata is sure Ipswich will provide Manchester United with a stiff test in the Capital One Cup tonight.
United moved up to second in the Premier League on Sunday with a 3-2 win over Southampton.
Confidence is riding high at Old Trafford following their successful start to the campaign, but Louis van Gaal knows better than most that the League Cup can spring an almighty surprise.
Three games into last season, Van Gaal suffered the most humiliating defeat of his reign when United were beaten 4-0 by MK Dons in the second round.
Mata was not playing that night, but being a student of the game, he knows all about Ipswich's history and knows the potential is there for the Sky Bet Championship high-flyers to cause an upset.
"On Wednesday we start in the Capital One Cup against Ipswich Town. They are a historic team in English football and I'm sure it won't be an easy game for us," the United playmaker said of the Tractor Boys, who won the FA Cup and UEFA Cup under Bobby Robson, as well as the league in 1962.
"After that we play against Sunderland, they need the points and they will come to Old Trafford trying to win. We hope to play good and be successful on both games.
"It would be a joy for everybody."
Mick McCarthy has already registered one upset against Van Gaal, although it did come 14 years ago and the pair were in charge of very different teams.
McCarthy, then in charge of the Republic of Ireland, ended Van Gaal's hopes of guiding Holland to the 2002 World Cup with a 1-0 win for the hosts at Lansdowne Road in September 2001.
The Dutchman, who resigned his post four months later, looks set to ring the changes for the third round tie at Old Trafford on Wednesday.
Andreas Pereira, James Wilson and Jesse Lingard could all feature, although the latter two did play the full 90 minutes of United's Under-21 win over Everton on Monday.
Marcos Rojo and Marouane Fellaini are short of match practice, too.
Sergio Romero has not played since David de Gea signed his new contract, but the Argentinian may still be on the bench on Wednesday.
Van Gaal selected De Gea in the cup competitions last year and the United boss said recently he did not "support" the idea of rotating goalkeepers.