We take a look at the key factors that could unfold as the promotion rivals battle it out at the top of the table.
So much rides on this game (Friday), which sees sixth-placed Donny host the Tykes, who sit second. Barnsley are desperate to keep Sunderland and Pompey at arms length. while Doncaster have Peterborough breathing down their neck.
Barnsley will go into the south Yorkshire derby as favourites. They're unbeaten in the league since December 8 - a run that stretches 17 games. Rovers remain in the play-off places despite no win in five League One games.
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Rovers boss Grant McCann has been full of compliments ahead of the game. He's even predicting the League One trophy ending up at Oakwell. He said: 'It wouldnt surprise me if they went on a run and won the league.'
The Hatters, who are five points clear of Barnsley play host to 17th-placed Gillingham. Mick Harford's side are on a 24-match unbeaten run. The Gills lost their last game against Bristol Rovers, at home, in midweek.
Remote, to say the least. But Luton could be without midfielder Alan McCormack. Harford said: 'Alan's pivotal in that position, but that's why we bolstered the squad. We knew we'd have injuries or suspensions one way or the other.'
Sunderland, who sit third, are at home to Walsall. Along with Luton and Barnsley, Jack Ross' troops are unbeaten at home in the league this season. Meanwhile, the Saddlers have lost their past three on the road.
Ross: 'This season has 12 or 13 teams that still have a realistic chance of being relegated which means there are an awful lot of teams with stuff to play for. Walsall fall into that bracket as well.'
There's a good chance. Despite losing to Charlton last week, the Blues are showing they could be coming back into form. Scunthorpe are four points off the relegation places and have suffered defeats in their past three away games.
The Blues could be without Ronan Curtis until after Easter. He has pulled out of the Republic of Ireland squad for their forthcoming internationals and could miss the Checkatrade Trophy final against Sunderland.
Scunny boss Stuart McCall is in no mood to roll over at Fratton Park. He said: 'Were looking forward to it, like we do every game. We know it will be a difficult match but well make it difficult for them as well.'
Charlton will be eager to make the most of any slip-up at Fratton Park. They could leapfrog the Blues in the table if results go their way. Standing in their way, though, is a Bristol Rovers side buoyed by two successive away wins.
Charlton could be without two of their top players. Krystian Bielik was subbed at half-time during Charltons 2-1 win over the Blues, while Joe Aribo has been suffering from an illness since Tuesdays win against Burton Albion.