MIKE Williamson praised Aaron Martin for his contribution to Oxford United’s defensive effort after coming on as a substitute in the 1-1 draw at Milton Keynes Dons.

A hamstring injury to Dwight Tiendalli forced a reshuffle in the back four after just 28 minutes.

Christian Ribeiro, who had started at centre half, filled the gap in his more favoured right back role to make room for Martin.

The 27-year-old has struggled to establish himself due to a combination of injuries and patchy form since joining last summer.

But he performed well as United came under heavy pressure, impressing his central defensive colleague.

Williamson said: “It’s always hard as a centre half to get into the tempo of the game because if we make a mistake it costs us.

“It’s different for strikers, they can make ten mistakes and if one goes for them they’re a hero.

“The discipline he showed after coming on I thought he was fantastic, one of the men of the match for me.”

The fact Ribeiro, normally a right back, was preferred ahead of Martin in the XI was seen as an indication of where the former Southampton trainee was in the pecking order.

But boss Pep Clotet felt in this instance, the way MK Dons played favoured Ribeiro.

He said: “When their striker ran in the channel he normally ended up in a full back’s position.

“We knew that would happen, so Ribs would fit that perfectly, but when Aaron went in he did a fantastic performance.”