United are one of five clubs chasing second place in League One on what promises to be a dramatic final day of the season.
Victory over Bristol Rovers will be enough to clinch runners-up spot behind champions Norwich City regardless of how Millwall, Swindon Town, Charlton Athletic and Huddersfield Town fare in their own games.
A draw or defeat would, however, change the promotion picture dramatically with United fans left nervously waiting for news from elsewhere.
It means today could be a nervy affair at Elland Road and Bates, who is confident Simon Grayson's men will claim the required three points against Rovers, is hoping the capacity crowd stick with the Leeds players regardless of how the game is panning out.
The United chairman said: "Everyone is looking forward to the game and is in confident mood.
"It won't be easy as Bristol Rovers will be determined to spoil our season, especially as we beat them 4-0 away from home.
"But with nearly 38,000 people inside Elland Road all fully behind the team, we can do it.
"It will be a nervy day, I am sure of that after having been in
football for 40 years.
"But Simon is selecting a team that will go out there to win the game. If we do that, we are promoted. It is quite simple, though I am always reminded of something the late Tony Banks once said to me before an important game at Chelsea. We were in the stand and he said 'it is a simple game from up here – we never miss a penalty, never make a mistake and never score an own goal'.
"The fans have to realise that and stick with the players. We need them to show plenty of patience and let the players know they have the fans' full support.
"If the fans can make the players feel 10ft tall, everything else will take care of itself."
Leeds are in the driving seat due to being the only club whose fate is in their own hands. Such has been their collapse in form since the turn of the year, however, that nothing can be taken for granted.
After losing just once in the first half of the season and being eight points clear at the top on New Year's Day, United have struggled for both form and results.
In the 22 league games played in 2010, they have claimed just 27 points and only the stumblings of others have allowed Leeds to remain in second place going into the final game.
Last weekend, for instance, saw Millwall blow a golden chance to leapfrog United in the table when they lost 2-0 at relegation-threatened Tranmere Rovers.
With Swindon and Huddersfield both winning as Grayson's men lost at Charlton, it means five clubs still have a mathematical chance of claiming second place.
Of that quintet, two – Millwall and Swindon – meet at The Den while fifth-placed Charlton Athletic travel to Oldham Athletic as Huddersfield make the long trip to Exeter City.
Terriers manager Lee Clark admits his side are "massive outsiders" due to being three points behind Leeds and needing all the other results to go in their favour.
Huddersfield, like Charlton, need the encounter at The Den to end all square for them to retain any hopes of sneaking into second place come 5pm.
Millwall and Swindon, meanwhile, are relying on a favour from Bristol Rovers, whose manager Paul Trollope has this week been inundated with offers of help from the clubs hoping to capitalise on a slip by the Yorkshire side.
Trollope said: "I think we have received more help this week from other clubs than we ever have in the past, which is great.
"We have had an influx of information, DVDs of Leeds games and reports, which can only help us. Hopefully, we will be able to act on it."
Trollope is hoping that a season where fans have learned to expect the unexpected in League One will have one more dramatic twist on the final day.
After more than four decades in football, Bates is well schooled in the sport's propensity to shock but the United chairman insists the Elland Road players have the character to finish the job.
He said: "I have been involved in a few nervy final days. I remember Chelsea going to Bolton in 1983 when the winner would stay in the Second Division. It was chucking it down that day and the pitch was like a gluepot.
"With the tension that also surrounded the game, it meant it was a nervy affair for everyone. But then Clive Walker scored 20 minutes from time and Chelsea stayed up.
"The following year, Chelsea won promotion to the old First Division and clinched the championship on the final day by beating Grimsby 1-0. Chelsea just pipped Sheffield Wednesday to the title that year.
"The key is going out there in confident mood and to match that confidence with aggression. I am sure Simon and his staff have been working hard all week in making sure that is the case."
P W D L F A Pts
Norwich 45 29 8 8 89 45 95
Leeds 45 24 11 10 75 43 83
Millwall 45 23 13 9 73 42 82
Swindon 45 22 16 7 71 54 82
Charlton 45 22 15 8 69 48 81
Huddersfield 45 23 11 11 81 54 80
Southampton 45 22 14 9 82 46 70
Colchester 45 19 12 14 63 52 69
Bristol Rovers 45 19 5 21 58 68 62
Brentford 45 14 19 12 55 52 61
MK Dons 45 17 9 19 59 66 60
Walsall 45 15 14 16 58 62 59
Brighton 45 14 14 17 55 60 56
Carlisle 45 14 13 18 61 66 55
Yeovil 45 13 14 18 55 58 53
Oldham 45 13 13 19 39 55 52
Leyton Orient 45 13 12 20 53 62 51
Gillingham 45 12 14 19 48 61 50
*Hartlepool 45 14 10 21 59 67 49
Exeter 45 10 18 17 46 59 48
Tranmere 45 13 9 23 42 72 48
Southend 45 10 13 22 50 69 43
Wycombe 45 9 15 21 53 76 42
Stockport 45 5 10 30 35 92 25
* deducted three points for ineligible player.
Today's key promotion fixtures
Exeter v Huddersfield
Leeds United v Bristol Rovers
Millwall v Swindon
Oldham v Charlton