Sir Alex Ferguson is happy with the transfer business he has done so far this summer but admits he could bring in at least one more new player before the transfer window closes.

Speaking at a press conference to officially present new recruits Shinji Kagawa and Nick Powell, Ferguson admitted that it was always harder to make signings when there was a major tournament taking place.

But he is now looking to strengthen his squad ahead of the new Premier League campaign, when United face the challenge of trying to regain the title they lost to neighbours Manchester City.

"We could possibly bring one, maybe two, more in," said Ferguson.

"When there's a major international tournament on, there's a delay in the transfer market. But now the European Championships are over, we're trying to bring someone in."

Ferguson is delighted to have snapped up Powell from Crewe and Kagawa from Borussia Dortmund, and hopes they will make an impact for the club.

He said: "We've always done well in terms of getting players at the end of season, instead of waiting all summer.

"In Kagawa's case, there was a fair bit of negotiating and that kept going for weeks. As for Powell, we knew Dario Gradi [Crewe Alexandra director of football] would help us do the deal quickly."

Discussing Powell's best position, Ferguson added: "I asked Dario if Nick could be a central midfielder. Dario thinks that's his position and Nick does too so we're all in accord. We hope he'll be a central midfield player and that's where we'll develop him."

Ferguson is excited about the sort of impression Kagawa could make in his debut season, having helped Dortmund win the Double in Germany last term.

"He'll play further forward [than Powell]. We shouldn't be looking at one player changing the way we play but he could make a difference," said Ferguson.

"He can give us that extra in the final third of the field. If his goalscoring record continues he could be a very good player for us."

Meanwhile Ferguson repeated his claim that Paul Pogba, who has left for Juventus, treated the Red Devils with a "lack of respect".

"We were disappointed in Paul Pogba, there is no question about that," said the Scot.

"He showed a lack of respect to the club.

"But he has made his decision now.

"Although we always felt he was going, he never indicated it until he left. That was disappointing."