As Sergio Aguero's brilliant second goal flew in against Swansea City on his Manchester City debut, plenty of people pointed out that's what £35 million buys you these days. In theory, anyway. Liverpool's fans might tell you otherwise.

They have one of their own, you see, but their version is about as similar to Sergio Aguero as Scott Minto is to Mark Bolton. Since arriving at Anfield from Newcastle United for the princely sum of £35 million in January, Andy Carroll has been a little like a fish out of water. Or, to put it another way, like Chris Sutton at Chelsea. Sutton was also a typical English target man who found himself unsuited to a more cerebral style of football after leaving Blackburn Rovers for £10 million. He never found his feet and Chelsea never found his head.

Of course, it's far too soon for Liverpool to panic about Carroll yet, and he has plenty of time both to launch himself at deliveries from Stewart Downing and Charlie Adam and develop a partnership with Luis Suarez. It didn't quite work out like that in the 1-1 draw against Sunderland on Saturday, but Carroll at least has an excuse about his disappointing performance: He was being marked by the imperious Wes Brown.

If Aguero's was the stand-out debut of the opening Premier League debut - and let's face it, it was - then Brown's wasn't far behind. A few eyebrows were raised when Sunderland signed him from Manchester United this summer. There tends to be when a player leaves Old Trafford for a smaller club. There are doubts over whether the desire and intensity will remain, or whether the player is simply in it for the money. More importantly, if Sir Alex Ferguson is letting him go, there has to be a reason, no matter how many trophies the player has won.

The main challenge for Brown is staying fit. When Sunderland fans heard their new signing from United was going to miss their first game with a hamstring injury, they could have been forgiven for instantly assuming it was Brown who was out. Instead it was John O'Shea , incidentally another underrated and excellent piece of business by Steve Bruce. Granted a run of games, Brown operates as smoothly as Don Draper making himself an Old-Fashioned; his problem has been avoiding the treatment table long enough to do so. Often shaky after a return from injury, he has sometimes made spectacular mistakes which have led people to assume incorrectly that he is a slightly classier Titus Bramble.

In 15 years at United, Brown played 361 games. Perhaps it should have been more. But he has suffered a similar fate to Ledley King and Jonathan Woodgate: prodigiously gifted defenders let down by their unreliable bodies. Brown has not suffered as much as the other two; after all in 2008, he was a key part of United's double-winning side as their right-back and even provided the cross from which Cristiano Ronaldo scored in the Champions League final win over Chelsea. However, he was unable to avoid injury long enough to cement his place in the side, and Rio Ferdinand and Nemanja Vidic, not to mention Chris Smalling, Jonny Evans, Phil Jones and the Da Silva twins made him surplus to requirements. Far better to be playing regularly in the league than to be handed token appearances in the Carling Cup anyway.

The early evidence suggests that Brown is more Phil Neville than Nicky Butt. Against Liverpool, he hardly gave Carroll a sniff - tackling well, dominant in the air, and intercepting danger alertly. You need to be tough to deal with Carroll. Brown is, deceptively so. On the Sunderland fansite, Roker Report , Simon Walsh awarded him 9/10 and called his display a masterclass in defending . Indeed the closest Carroll went to scoring was when he pulled on to Brown's defensive partner Anton Ferdinand in the first half, brought down a high ball from Adam and lashed it past Simon Mignolet, only to be penalized for a foul on the defender. After Suarez had headed Liverpool into an early lead, the hosts threatened to over-run Sunderland, who gradually became more assured and eventually snatched an equalizer through Sebastian Larsson's cracking volley.

Bruce was delighted with what he had seen from Brown, and echoing comments regularly made by Ferguson, he claimed he is arguably the best natural defender in England.

"Wes Brown showed what a great defender he is," said Bruce. "Wes rolled back the years. That's his first game for months. If he stays fit and we get O'Shea back, we'll be a better team than last season."

He's got that right. Brown and O'Shea are valuable not only for the individual qualities that they offer, but also for their professionalism and their ability to make a talented but dozy player such as Anton Ferdinand up his game.

Bruce is regularly mocked for turning to United during transfer windows. Maybe not this time.