Marcos Rojo signed for Manchester United for £16m to plug a hole in their porous defence.
The Argentina star played left back for Argentina in the World Cup and on his debut for his new club at Old Trafford against Queens Park Rangers.
But he will be played more through the middle, possibly starting against Leicester City this weekend, and here our Portuguese blogger Goncalo Lopes, who watched Rojo extensively for Sporting Lisbon, rates him as a left back and centre half.
Marcos Rojo played left back against Queens Park Rangers but could play centre half against Leicester City
Marcos Rojo is a better left back than a centre half, in my opinion. Here in Portugal he played almost all of Sporting Lisbon's matches at centre back but for Argentina, he deployed is on the left side of the defence.
At left back he has more confidence - he made more interceptions, tackles and even completed a greater number of passes playing there. As we say in Portugal, at full back he is 'on the beach'.
As a centre back - where he played the majority of his games for Sporting - he prefers to use his physicality and his excellent anticipation to disturb his opponents on the ground, but he could do better in the air. He is also sometimes found wanting in his marking and positioning, which for a player in that position is crucial.
The Argentina defender (right) played most of his football at Sporting Lisbon in the centre of defence
Marcos Rojo: Manchester United transfer was long and tough
Rojo (left) showed he is not afraid to put in a challenge during his Manchester United debut against QPR
However, don't think he will make mistakes in all of his matches. Rojo is the kind of footballer that has an excellent game one week but then his weaknesses appear in the next game, particularly at centre half.
He is not a panicker. When he plays left back, Rojo is able to go forward with possession. He is good on the ball, has excellent vision and the eye for a pass in attacking areas. He made plenty of goals for Sporting last season.
But to do a great job at centre back, he has to have an excellent covering defender at his side. Here in Portugal he did well because he played with a great partner, Mauricio - they conceded 19 goals in 29 games, the fewest in the Primeira Liga - who had more experience in that position.
The defender's disciplinary record at Sporting Lisbon was not brilliant and he was sent off five times last year
Rojo could be deployed at centre half when Manchester United travel to Leicester City this weekend
Although he was often played at centre back, Rojo struggled unless he had an experienced player alongside
Rojo likes to have a hit from range as this compilation shows
If Rojo does not have a solid player alongside him, however, there will be more mistakes.
I can say that the £16million which Manchester United paid was for Marcos Rojo the left back - he isn't worth that kind of money at centre half.
He can still do it but not with the same effectiveness as in his favourite position of left back.
It will be a tough examination for Rojo at centre half in a porous United defence vs the newly-promoted Foxes
Rojo was deployed at left back for Argentina during the World Cup, when they reached the final in Brazil
Follow Goncalo Lopes on Twitter @_GoncaloLopes
More...
Manchester United treble winner Jonathan Greening has joined non-league outfit Tadcaster Albion
Wayne Rooney is 'an absolutely hilarious character' who 'likes a drink' say Piers Morgan after England captain got stuck in a plant pot following boozy dinner
Radamel Falcao takes a family stroll as Manchester United star explores the city
Man Utd have an embarrassment of riches when it comes to free-kick takers but will it be Angel di Maria, Juan Mata, Wayne Rooney, Robin van Persie or Radamel Falcao entrusted with set-piece duty?
Cristiano Ronaldo, Lionel Messi and John Terry feature in Frank Lampard's best XI
Luke Shaw will be the best left back in the world, says Manchester United team-mate Jonny Evans
Arsene Wenger reveals his biggest regret is missing out on Cristiano Ronaldo
Louis van Gaal is the new 'Tinkerman'... Manchester United boss has used 33 players in five matches this season, five more than any other Premier League side
Source: dailymail