Byron Webster misses Carlisle United's game against Grimsby today due to concussion protocols.

The centre-half was hurt late in Tuesday night's FA Cup win against Forest Green.

After Webster was substituted, following a collision with team-mate Canice Carroll, Blues boss Chris Beech said guidelines meant the defender could not play for another week.

The United head coach said: "Byron was poorly - not that bad, he’s got a cold - but he gave everything on Tuesday.

"When the body goes into physical red zones, and the rain’s coming down like it was, and his own player tackles him from behind when he doesn’t expect it and he hits the floor harder than a boxer…it just threw him a little bit.

"We’ve had to do the FA protocol for it, so he will miss seven days."

Webster was replaced by Nathaniel Knight-Percival in Tuesday's closing stages.

It came after the ex-Millwall man had given a strong performance in United's back four.

Beech said the unfortunate incident summed up the commitment of his team in the midweek FA Cup replay.

"If we keep working that way, with those traits, that real burning ambition to not get beat, we’re going to get little speed bumps, knocks on the way, and that was one," Beech said.

"In the endeavour to make sure we win that game, Canice has ended up tackling Byron.

"It’s one of those things, but it’s somebody else’s opportunity [now] Hopefully they’ll fulfil it."

Beech also repeated his view that some of the recent criticism of Webster has been harsh.

He feels there has been too much focus on the defender.

"It’s amazing sometimes what you see and hear," he said. "I often think, 'why?'. It doesn’t make sense from what I’m hearing and seeing.

"He made one mistake the other day [Tuesday], passed the ball five yards, but got it back within two or three seconds, that was it.

"There’s other players making plentiful mistakes, but for whatever reason they’re allowable; when he makes one it’s not. I don’t really understand that fact."