Dundee United boss Jackie McNamara last night hit back at Ronny Deila as the war of words between the two clubs escalated - and accused the treble-chasing Celtic manager of inflaming the situation.

McNamara spoke out ahead of today's Scottish Premiership clash in Glasgow which will be the fourth encounter between the sides in the past fortnight. The first three yielded six red cards.

Deila branded United defender Ryan McGowan's tackle on Liam Henderson as 'career-threatening' after Celtic had won Wednesday night's Scottish Cup quarter-final replay 4-0 at Parkhead, having earlier accused Tannadice youngster Aidan Connolly of diving in the 1-1 quarter-final draw at Tannadice.

Now, McNamara has criticised the Norwegian while acknowledging that 'enormous' pressure may have been a factor in triggering his recent outbursts.

The former Celtic defender said: "Everything has just kind of boiled up over the last two weeks, but I understand the pressure Ronny Deila is under.

"He's under pressure to succeed and win a domestic treble because of the money they've spent and the resources they have. Celtic are under enormous pressure because of the Champions League and I understand that.

"They should be winning domestic trebles because they have spent a lot of money and nobody is close to them. With the resources Celtic have they should be winning all three trophies. His words are not accurate or helpful, speaking about players like Aidan and now Ryan. But I understand he's under pressure and that has been reflected in his comments.

"The pressure is enormous on the guy to win a treble. For me there hasn't been any real dangerous tackles. We need to get a bit of perspective here. But that's down to pressure. We're all under pressure but using words like 'career-threatening' and singling out players, I don't think the Celtic manager should be doing that.

"He'll do things his own way, but for me he's under pressure and sometimes these things boil over."

McNamara felt Deila was way over the top in his criticism of Australian international McGowan's challenge on Henderson as the Glasgow giants stayed on course for a clean sheep of domestic trophies in midweek.

He pointed to the the fate suffered by Celtic coach John Kennedy, who was forced to retire in the wake of a shocking late challenge by Romanian Lionel Ganea on his Scotland debut in March 2004, as the kind of challenge that can do lasting damage.

McNamara said: "Ronny has a guy on his coaching staff whose career was ended by a challenge. The one on John Kennedy was a career-ending challenge. It was an absolutely shocking challenge. That was a bad challenge. So to say that about Ryan's challenge isn't right. His was committed - he put everything behind it but he's not hurt the lad. The lad has played on.

"We have never come out and criticised anything in the last two weeks, but I understand the pressure he's under. The biggest injury over the last three games was the one on Sean Dillon, but that was an accident and that's football. Sean has a lot of stitches in his shin now because of it. You can't say it was meant or a bad challenge, it just happened. That's football."

McNamara was unhappy that teenager Connolly had been tagged a 'diver' by Deila, but insisted he did not have a problem with him professionally.

McNamara said: "It started with the comments about Aidan diving and it has just escalated from there with the challenges and the sending-offs. We had a young kid coming onto the pitch at 19 years old and he was booed on because of the comments from the first game.

"That's an opinion and now the young lad has a tag. He's getting booed by fans on the back of it. He's only 19 years old.

"My relationship with Ronny has been fine, after the first game he came into my office. After the final we went our separate ways - unfortunately he left with the trophy. And the other night we had a chat after the game and nothing was talked about. I have no problems with him. I just don't think he should be saying things like that.

"We are appealing Ryan's red card because, for me, it should never have been a sending-off. We have to appeal it because I don't think it's a bad challenge at all."

United must lift themselves for today's trip to the home of the league leaders but McNamara remains hopeful they can end their 23-year long Parkhead jinx.

He said: "Three games in six days is not ideal and things would be easier for us if we'd won one of the games. But we have to stick together and make sure we don't give any poor goals away. It's important we don't give away goals.

"There's plenty still to play for this season. We've done well to get to a cup final and playing them away in a Scottish Cup replay is always tough. We have not beat Celtic in Glasgow for 23 years. That's a long time but it's something we hope to change."