Jamie Redknapp has taken aim at Erik ten Hag after Manchester United's decision to move for Lisandro Martinez over Pau Torres.
£55m defender Martinez impressed under Ten Hag at Ajax and followed the manager to Old Trafford. However, after a nervy debut against Brighton & Hove Albion, he endured a torrid time as United were thrashed 4-0 by Brentford.
The 24-year-old struggled under pressure from Ben Mee as the defender scored Brentford's third goal, prompting questions about his physical capabilities. It was clear Martinez was the pick of the manager rather than the recruitment team, and pundit Redknapp sent a reminder to the United boss.
"If you're going to sign a 5'9" centre-back, now I've watched Premier League and played in the Premier League and he's not going to be able to compete in this league," Redknapp said on Sky Sports. "He might be okay in the Dutch league, where it's not quite as physical.
"But when you play here you know, week in, week out, teams are going to be looking to expose any weakness like Brentford did today, like Brighton did, like Liverpool will do. Everyone will play on him because he's 5'9", he's not tall enough - he's actually a small midfielder, let alone a small centre-back.
Villarreal and Spain star Torres had long been on United's radar, and played against them in last season's Champions League. United's higher-ups had earmarked the centre-back, only for Ten Hag to reportedly veto a move.
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Redknapp said the Martinez deal is one of the transfers Ten Hag will be judged by. However, he was more enthusiastic about midfield target Frenkie de Jong.
"I do believe that Frenkie de Jong, if he comes in to the club, will improve this team because he's a fantastic midfield player," Redknapp continued. "They are so short in that department.
"All the great midfield players that have played for the club, right now they're devoid of any real quality in [that] area. He played Christian Eriksen as a false nine last week [against Brighton], this week he plays him as a deep-lying midfield player.
"Now, as a manager I'm thinking that's not great tactically. You have to be careful you don't get too many decisions wrong early days."
United's season doesn't get any easier, with Ten Hag's team hosting Liverpool at Old Trafford on August 22. Last season's corresponding meeting between the two teams saw Jurgen Klopp's men run out 5-0 winners, with the Merseyside club also triumphing 4-0 in the more recent meeting at Anfield.
