Manchester United boss Sir Alex Ferguson arranged to watch talented Benfica midfielder Axel Witsel during the Portuguese outfit's Champions League quarterfinal first leg against Chelsea on Tuesday night, according to U.K. newspaper the Times.

With Witsel having just signed a five-year contract at Benfica, following his move from Standard Liege last summer, the report said United's offer will have to exceed £20 million ($32 million) to have any chance of tempting the Lisbon giants to sell.

Witsel has impressed in his first season in Portugal and is likely to be the subject of interest from a host of sides across Europe, if Benfica is prepared to sell.

The 23-year old has already appeared 27 times for Belgium, scoring five times.

Central midfield is a position that has long been seen as a weakness at Old Trafford. With the future of Darren Fletcher somewhat unclear and Anderson, who has never fully established himself, continuing to suffer with injuries, it is likely that Sir Alex Ferguson will look for reinforcements in the middle of the park come the summer.

Another midfielder who Ferguson is reportedly considering adding to his squad is Athletic Bilbao's Javi Martinez.  And the website Caught Offside is reporting that United will make a £20 million offer for his services come the end of the season.

With so many incessant rumors, it would seem there is some truth to United's interest in the 23-year-old Spanish international. However, it would be a surprise if there were many top clubs around Europe who had not cast their eye over the technically-gifted holding midfielder.

With Athletic, as it showed in spectacular fashion by knocking the Red Devils out of the Europa League, building an exciting young side at San Mames, it isn't going to sell a star player on the cheap.

A more attacking midfielder that has been linked with United is Lille's Eden Hazard, an international team mate of Witsel.

Caught Offside also reported that Ferguson has persuaded the United board to sanction a bid of up to £35 million for the 21-year-old, who can be deployed either in the hole or wide in a front three.

There certainly appears to be foundation in Ferguson's interest in Hazard, another of the most coveted players in Europe. The United boss was spotted taking in Lille's 2-1 defeat at Lyon earlier this month.