Republic of Ireland midfielder McGeady returned this week to training after being suspended from first-team duties for a fortnight and fined two weeks' wages following a dressing room bust-up with Strachan in the wake of last month's 1-1 draw with Hearts.

McGeady failed to even make the bench for the Clydesdale Bank Premier League visit of United, fuelling speculation about his future at Celtic Park.

However, Strachan pointed to the SPL rule that dictates three outfield players of 21 or under should be in each match-day squad.

Asked the reasons why McGeady was missing, Strachan replied: "The reasons are that I wanted to stay faithful with the squad that played so well in the last two games.

"Also, everyone knows about this under-21 rule which we have complained about consistently since I have come here - as have other managers - but there is no change."

McGeady looked to be no big loss when Georgios Samaras scored in the 12th and 57th minutes to give the champions what looked like to be a comfortable lead.

However, in a dramatic turnaround, Paul Dixon reduced the deficit on the hour mark with a wonderful free-kick and Warren Feeney, on for Danny Swanson, grabbed a dramatic 77th-minute equaliser.

Celtic go eight points clear over Rangers at the summit but the Ibrox men have the chance to reduce the deficit to five when they take on Inverness tomorrow.

Strachan claims his side stopped playing "common-sense football" after scoring their second goal.

He said: "I was happy with the chances we made in the first half, and if there is anything we regret, it's that we didn't take them.

"We didn't start the second half very well but we got the second goal.

"I thought we could have got through with common-sense football but we didn't play common-sense football, as you saw.

"And from being 2-0 down, United got a goal from nothing.

"It was a lovely free-kick but I think you will all agree that we had three chances to clear it.

"They got re-energised and played very well after that.

"But, whatever way you look at it, the secret of football is being able to pass the ball to each other and we didn't do that as well as we did in the first half."

Two-goal Samaras claimed the latter part of the game for Celtic was the equivalent of football "suicide".

The Greece international said: "We committed suicide. When you are two-nil up, you cannot lose two points; that is unacceptable.

"We played well in the first half but our performance in the last 30 to 35 minutes was really bad. I don't know why that happened."

United manager Craig Levein played down speculation skipper Lee Wilkie, who has yet to sign a new contract, could be on his way out of Tannadice.

Wilkie has been linked with a move to Rangers but Levein said: "I don't know anything about it. I have made Lee a contract offer and he will tell me next week.

"I'm quite philosophical about all these things.

"If Lee has decided his future is elsewhere then he hasn't indicated that to me and I certainly know nothing about interest from any other teams.

"Of course I want all players to stay but I'm not stupid enough to think they will.

"I have a lot of good players and I may have to sell some eventually; the difficulty is always trying to find new ones."

Levein feared his side became too excited after clawing back the two-goal deficit.

"It's not often that you score two goals here, certainly not coming from two goals behind," he said.

"We could have won the game but we could also have lost it.

"We got so excited that we were charging forward and I was worried that we might lose a goal.

"At one point, Garry Kenneth was crossing the ball, Wilkie was in the box and Morgaro Gomis was playing centre-back.

"That wasn't part of the plan, I can tell you that."