KARL Robinson felt Oxford United stepped it up a notch after his quadruple substitution against Cambridge United.

The U's head coach brought on Marcus McGuane, Liam Kelly, Mide Shodipo and Derick Osei on the hour mark, with the Papa John's Trophy third round tie goalless.

Among the players to come off were Cameron Brannagan and Sam Winnall, starting their first games since returning from injury, and Jamie Hanson, who only left the treatment room last month.

Read also: Karl Robinson hints at no more Oxford United exits this month

While Rob Hall, one of United's starters, grabbed the winning goal, Robinson felt his side became more dynamic after the changes.

McGuane, Kelly and Shodipo have been regulars in recent weeks and the U's boss thought their fitness showed.

He said: “Even though the names (in the starting line-up) were exciting, we always knew there was going to be some sort of lack of energy.

"I think you saw a clear energy when we made the substitutions.

"That’s not because they’re any better, it’s purely because they’re fitter and more game-ready.

"I had a little bit of a hissy fit at half-time.

"I just asked for a bit more in certain areas and I think we got that as the game went on.”

Read the match report here

Cambridge had already beaten three higher-division teams in the cups this season and made the U's work hard for the victory.

Boss Mark Bonner was satisfied with his team's defensive effort, but was full of respect for United.

He said: “Credit to them because of how they pressed us and how big they make the pitch.

“We knew it was going to be a really tough night for us.

“We had to work our socks off to contain them and in the main we limited them to a few chances.

“They didn’t play through us too often, unless it was a counter-attack.

“There were too many set-plays and too many fouls, but those things become a constant when you’re stretched.”

He added: “They’ve got some really good players and just got stronger with the changes.

“I was really impressed with them.”