That would be an odd time for even Chelsea's owners to make a change, just before a critical Champions' League tie away to the accomplished Napoli, but it is clear that much more of this and the end of the road will arrive much sooner for a bright young manager than he would have expected.
There are some things no manager can control. Had Colin Doyle, Birmingham's second-choice goalkeeper, not made a superb diving save from Juan Mata's penalty immediately after David Murphy put the Championship side in front, then, as Villas-Boas claimed, the eventual outcome would almost certainly have been different.
It was significant that Mata, not Fernando Torres, was on penalty duty and the confidence of the £50m striker can only have been further shredded by being removed at half-time after yet another inconsequential performance. He has now gone 20 games since a goal, way back in October, when it briefly looked as if things might be turning his way.
With John Terry and Ashley Cole injured – both are doubtful for the Napoli game – Villas-Boas also kept Frank Lampard, Michael Essien and Didier Drogba in reserve, hoping the younger "new Chelsea" replacements would have enough about them to see off a team sixth in the League below. Not so. Birmingham, unbeaten in 14 games under the impressive Chris Hughton, threatened at set pieces, defended with discipline and were well worth the replay that will have St Andrew's shaking in just over a fortnight's time.
The "Bosman Blues" as they have been called after a new squad was put together on free transfers after relegation last May, were even missing their two main strikers, Marlon King and the lanky Nikola Zigic, as well as losing their captain Stephen Carr after only a dozen minutes.
They played five in midfield with a striker by the name of Rooney – Adam – working hard up front and the 17 year-old Nathan Redmond showing flashes of his precocious talent down the left. At the back Curtis Davies and the former Spanish international Pablo Ibanez stood firm until one crucial moment just after the hour when they lost Daniel Sturridge, who headed the equaliser.
Ibanez was once a team-mate of Torres at Atletico Madrid and must have been aware of how wretched is the former golden boy's form. Torres had failed miserably to seize his opportunity while Drogba was away at the African Cup of Nations. He had one good moment here, heading down a long clearance for Sturridge to volley just past the angle. Again the service was poor from an insufficiently creative midfield of Ramires, John Obi Mikel and Raul Meireles, and Chelsea only improved once Sturridge was given his wish to play more centrally, with Mata moving off the flank to play behind him and Drogba, who replaced Torres at half-time.
"An excellent performance in the second half, compared to the first," Villas-Boas said, which was one way of looking at it. "The aggressiveness, desire and ambition were there but Birmingham matched us for that and their goal gave them further motivation. You can never be satisfied when you draw at home to a Championship team and it was not good enough." To the inevitable questions about Torres he replied: "Fernando is a super talent. Eventually things will get better for him and as he gets back to his goals he'll have more confidence."
The problem, of course, is that Chelsea cannot afford to indulge their absurdly expensive striker any longer when there are games to win, or to save. So Drogba came on to encourage a more direct approach, having first been seen delivering his own pep talk to team-mates in the tunnel.
Nothing much happened for 20 minutes, except that Carr, Birmingham's experienced right-back, was forced off with a recurrence of recent knee trouble. Then Redmond won a corner on the left which several different Chelsea defenders failed to clear, allowing the left-back Murphy at the far post to drive a shot past Petr Cech. The home side immediately put together their first coherent move, which was ended when Wade Elliott tripped Ramires. Mata's penalty was by no means badly placed, but Doyle modestly admitted to "guessing right" and sprawling down to push the ball against a post.
Before the interval, he turned David Luiz's fine free-kick over the bar and held Mata's header. He was let down by his defence, however, in the 61st minute after Mata swept a pass to Branislav Ivanovic, whose perfect cross was neatly headed in by an unmarked Sturridge. "I'm even more delighted with the performance than the result," said Hughton. "At 1-1 you'd think the emphasis could swing with them. I'd still see Chelsea as favourites but I hope we can give them as good a game as we did today."
Chelsea (4-3-3): Cech; Ivanovic, Cahill, Luiz, Bertrand; Ramires, Mikel (Kalou, 57), Meireles; Sturridge, Torres (Drogba, h-t), Mata (Lampard, 83).
Birmingham (4-2-3-1): Doyle; Carr (Spector, 12) , Davies, Ibanez, Murphy; Fahey, Gomis; Elliott (Burke, 83), Mutch, Redmond; Rooney (Jervis, 71).
Referee Martin Atkinson.
Man of the match Ibanez (Birmingham).
Match rating 6/10.
AVB watch
His tactics With a Champions' League tie at Napoli on Tuesday, Andre Villas-Boas kept half a dozen of his most experienced players as substitutes, before having to send three of them on to save the game. Even before half-time he switched from the original 4-3-3 to a 4-3-1-2, which worked better, with Daniel Sturridge moving into the middle as a second striker.
His demeanour The manager was as busy as ever on the touchline, where he spent most of the game, cajoling and directing. He responded to Juan Mata's penalty miss with a series of encouraging handclaps but had to endure booing from his own supporters when taking off the Spaniard to send on Frank Lampard.
His verdict In summary, better in the second half than in the first, but not a good enough result or performance. Confidence, he admits, is lacking and will only return to the team as a whole, as with Fernando Torres, when results improve. "It will be a difficult game at St Andrew's, where Birmingham are undefeated in the League."
His prospects The Napoli tie, he insists, will be decided over two legs, by which time there will have been three winnable League games and the Birmingham replay. Confident about his future? "It's not up to me to decide that."
Steve Tongue
Look who's ready to move in...
Chelsea and Arsenal will be on high alert after Pep Guardiola yesterday admitted he could leave Barcelona at the end of the season.
The 41-year-old coach, who has just three months left on his current deal, also denied he would only leave the Nou Camp to take a year away from football.
Guardiola, who has been at Barcelona for four years, said: "I can't be at such a demanding club with so many expectations without being certain that I have the strength to do it. I still don't have it clear in mind.
"I have always said that I am better off here than in any other place but to renew my contract I have to feel sure. I feel that it is better to have a bit more time. If that is OK then fine if not then too bad, I have to be true to myself."
Asked about the common perception at the club that he would only quit Barcelona to take a sabbatical, rather than move straight to another club he said: "That is not a decision that I will make now. I will make that decision when the time comes. Now while I am undecided I am thinking day-by-day".
Pete Jenson
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