Club captain Chris Morgan has warned the Blades that Saturday's opponents Colchester United should not be underestimated.

Morgs believes that Geraint Williams' side will prove to be a tough nut to crack, despite the loss of a number of key players.

Colchester saw last season's top-scorers, Jamie Cureton and Chris Iwelumo, winger Richard Garcia, centre-back Wayne Brown plus loanees Chris Barker and Hogan Ephraim flee Layer Road for pastures new during the summer.

However, the Us landed a significant coup with the capture of former Spurs forward Teddy Sheringham on a free transfer in July.

Chris, who is rated at 50/50 for Saturday's clash due to a niggling calf strain, said: "Colchester have had a few changes to contend with - the departures of Cureton and Iwelumo are big losses for them.

"They've done well to get Teddy Sheringham - he's a great footballer with a fantastic football brain."

The Us will this season hope to cement their position in the Championship following an excellent first season at that level in which they defied all expectations.

Colchester finished the 2006-07 campaign in 10th spot as Cureton, Iwelumo and Garcia grabbed 48 of the Us' 70 League goals last term.

Morgs says that visiting teams to Bramall Lane will look to knock the Blades off their perch because of their tag as one of the favourites for promotion.

He added: "I'm sure that opposition teams will want to come to the Lane and beat us. Managers will also want to put one over on Bryan Robson as he's a big-name manager.

"We've spoken about all that - we know people will come here and make it hard for us, but we'll be well prepared and it's up to us to do the talking on the pitch."