Both teams are already through to the playoffs, but places in the top two are still up for grabs, and any slip-ups in the closing stages of the league phase could land either Delhi Capitals or Chennai Super Kings in the Eliminator. It's not a situation either team wants to be in. Capitals have considerable momentum behind them, having won six of their last seven matches, but Super Kings come to this meeting with defeats in three of their last four games.
This slump in form can be read as a season-long weakness finally beginning to reflect in their results. Of all teams in the competition, Super Kings have been the slowest-scoring team in the Powerplay, with a run rate of 6.4 in that phase, and in the middle overs (7-15), where they have gone at 6.9. Two of their key batsmen, Ambati Rayudu and Kedar Jadhav, are this season's slowest scorers among all batsmen with a minimum of 100 runs to their name, with strike rates of 89.49 and 96.42 respectively. In third place, at 110.49, is another Super King - Faf du Plessis.
MS Dhoni's form (his 314 runs this season have come at an average of 104.66 and a strike rate of 137.11) could only cover these cracks for so long. It wasn't surprising that Super Kings, minus Dhoni, slumped to 109 all out, and their first home defeat of the season, in their last match against Mumbai Indians.
Apart from the fever that kept him out of the game against Mumbai, Dhoni has also had to deal with back trouble this season. Will he be back on Tuesday? We don't know yet.
"Dhoni is progressing," Super Kings coach Stephen Fleming said on the eve of the match. "He's been pretty sick during the week. We'll make a call on him tomorrow but he's progressing, which is good."
Whether Dhoni plays or not, Capitals will know it's never an easy task to play Super Kings at the MA Chidambaram Stadium. Their away record - five wins in six games this season - should give them confidence, but if they haven't been quite as good at home - three wins in six games - it's because they haven't enjoyed batting on the slow, grippy surface at Feroz Shah Kotla. Only one surface this season has been slower and grippier this season - the one they'll play on tomorrow.
Dwayne Bravo picked up three wickets at the death, and Capitals only managed 29 in their last five overs, leaving Super Kings a not-hugely-challenging 147 to chase. Shane Watson's 26-ball 44 gave them the early impetus, but the win took until the last over to arrive, thanks to a leisurely stand of 48 in 53 balls between Dhoni and Jadhav.
In the news
Like Dhoni, Ravindra Jadeja and du Plessis were also absent ill from the match against Mumbai. Unlike Dhoni, both have recovered fully. "Faf's been fine. Jadeja's also training well," Fleming said. "Definitely in consideration for tomorrow."
Chennai Super Kings: 1 Faf du Plessis/M Vijay, 2 Shane Watson, 3 Suresh Raina, 4 Ambati Rayudu, 5 Kedar Jadhav, 6 MS Dhoni/Dhruv Shorey, 7 Dwayne Bravo, 8 Ravindra Jadeja/Mitchell Santner, 9 Deepak Chahar, 10 Harbhajan Singh, 11 Imran Tahir
Delhi Capitals: 1 Prithvi Shaw, 2 Shikhar Dhawan, 3 Shreyas Iyer (capt), 4 Rishabh Pant (wk), 5 Colin Ingram, 6 Sherfane Rutherford, 7 Axar Patel, 8 Sandeep Lamichhane, 9 Amit Mishra, 10 Kagiso Rabada, 11 Ishant Sharma
Kagiso Rabada has played 18 games for Capitals/Daredevils in the IPL, and he's picked up two or more wickets in 11 of those matches. Of those 11 games, his team has won eight and lost three. When he's picked up less than two wickets, however, they've only won two out of five. These numbers suggest that teams are unable to go after the other Capitals bowlers if they suffer too much damage at the hands of their main strike weapon; perhaps there is a case for Super Kings to play Rabada out watchfully.
Colin Ingram has had an excellent IPL season against spin, scoring 91 off 64 balls while only being dismissed once. He's not been great against pace, though, scoring 80 off 62 while being dismissed six times. Rishabh Pant has been pretty good against spin - 152 off 108 balls, four dismissals - but devastating against pace - 191 off 105 balls, six dismissals. Spinners always bowl plenty of overs in Chennai, and which of these two left-handers bats at No. 4 and which one is held back to No. 5 could well depend on the phase of the innings and which bowlers are operating.
Jadeja has bowled 165 balls to right-hand batsmen in IPL 2019, conceding 161 runs and taking nine wickets. Against left-hand batsmen, he has bowled 75 balls, conceding 104 runs and taking no wickets. Mitchell Santner, on the other hand, has been excellent against left-hand batsmen (14 balls, nine runs, two wickets), albeit from a small sample size. Given the number of left-handers in Delhi's top order, however, Super Kings might be tempted to retain Santner even though Jadeja should be available, even if they aren't able to bring back du Plessis as a result.
Stats that matter
Super Kings have won 13 and lost six of their matches against Capitals.
If du Plessis features, he will be playing his 200th T20 match.
Dwayne Bravo is one short of 300 T20 sixes, and also one short of 50 T20 wickets at MA Chidambaram Stadium.
Suresh Raina has 49 fifties in T20 cricket.