The Everton right-back was given oxygen and carried from the field on a stretcher after being caught in the 69th minute of Friday’s fiery World Cup qualifier between the Republic and Wales in Dublin.
Coleman suffered a double break to his right leg and the 28-year-old underwent surgery on his tibia and fibula yesterday.
He is expected to be sidelined for the rest of 2017, a huge blow for both Ireland and Everton.
Wales manager Chris Coleman said Taylor had gone into the Republic dressing room after the game to see the Irish captain, although he did not think he had managed to do so.
Taylor spent eight months out of the game after breaking his ankle in 2012 and midfielder Allen said the Aston Villa defender was devastated by the incident.
“He’s in bits to be honest,” Allen said. “Tayls is one of my best mates and he’s a great guy. He’s really disappointed that one of his tackles has ended up getting someone hurt.
Joe Allen has revealed Neil Taylor is in bits after his horror tackle on Seamus Coleman
“But unfortunately in football these things can happen.
“There was no malice in the tackle and he certainly wouldn’t have intended to hurt anyone.
“I know him as well as anyone and I think everyone is disappointed, and from Seamus’s point of view it doesn’t look great.”
Allen was involved in the game’s first flashpoint just before half-time when he was caught by the swinging forearm of Stoke team-mate Glenn Whelan.
The two sets of players squared up to each other and, as the action became more fraught, the Republic believed Gareth Bale was fortunate to escape with a booking for his goalmouth challenge on John O’Shea.
Moments later Taylor went in hard on Coleman and Italian referee Nicola Rizzoli did not hesitate in brandishing a red card.
Get Quotes on Home Insurance
Joe Allen applauds the fans after Wales' goalless draw with Republic of Ireland
“He (Whelan) has given me assurances that he didn’t mean it,” Allen said of his club colleague.
“It happens when you come up against players you know, team- mates, and there’s no hard feelings at all. I’ll have to see it back. At the time I thought I was caught by an elbow. Who knows?”
Bale’s booking, his second of the competition, rules him out of Wales’ next game – the trip to new Group D leaders Serbia on June 11.
The Serbs’ 3-1 win in Georgia took them above the Republic on goal difference. Austria’s 2-0 victory over Moldova moved them level with third-placed Wales and four points behind the top two.
Allen said of the absence of talisman Bale in Belgrade: “It’s always disappointing when people miss out through suspension and we’re going to miss Gareth. But in our last campaign we had it. We’ve had games without Aaron (Ramsey) and Ben (Davies) – important players for us – and we’ll just have to cope with it.
“Serbia will obviously be glad that he’s not playing but we certainly feel we’ve got enough to go out there and overcome that.
Seamus Coleman being stretchered off the pitch after suffering a double leg break
“It’s still in our hands because we can take three points off everyone.
“We’re still unbeaten, which doesn’t count for that much, but we’re hard to beat and we’re not going to make it easy for anyone.”
Ireland striker Shane Long has backed Coleman to come back “fitter and stronger” from his injury, even though it was so gruesome that television bosses decided not to show replays of the incident.
Long said: “It’s not nice. I was trying to comfort him on the pitch. He’s loved by everyone, he’s a big player and he will be a big loss.
“He was in a lot of pain. It’s a bad injury, so I tried to settle him and relax him.
“It’s not nice to see that happen to anybody and I think everybody loves Seamus.
“I’m sure he will come back fitter and stronger.”