Sheffield Shield wrap: Pressure on Joe Burns, Mitchell Swepson's hub life, and Shaun Marsh as good as ever

There has been no shortage of in-form batsmen during the first three rounds of the Shield - 19 centuries have been scored - so when someone has struggled a little it stands out. Five of Australia's incumbent top seven are in action (David Warner and Steven Smith the two at the IPL) and all have made telling contributions except for Joe Burns. His three innings have brought 7, 29 and 0. The middle of those scores is probably the most frustrating as he had got himself settled before top-edging an indecisive pull. His second-innings duck, edging the superb Trent Copeland, came at around the same time that Will Pucovski and Marcus Harris were breaking records, while Sam Whiteman has also piled on the runs. Burns' returns last summer against Pakistan and New Zealand were solid rather than spectacular - two half-centuries in eight innings - although a substantial score in the final round of matches would probably see him retain his place. But the competition has suddenly become fierce.

Few players have gained as much from the tournament being forced into the single-city hub in Adelaide than legspinner Mitchell Swepson. The conditions have meant he has had a central role for Queensland and he has delivered with 15 wickets in two matches. He played a match-winning role in the opening game against Tasmania and came within a whisker of doing it again in the compelling match against New South Wales where he collected a career-best 10 for 171. Among that haul was the ripping legbreak from around the wicket to bowl Sean Abbott and another fizzing delivery to beat Daniel Hughes in the second innings. Australia will have to include a second spinner in their enlarged Test squad; it would probably have been Swepson in any case, but the last few weeks should have ended any debate.

It was only 12 overs, but they were another significant step in what is starting to feel like an inevitable Test debut for Cameron Green this season after his call-up to the limited-overs squad. Given his run-scoring it may not even matter how much he can bowl, but his return to action was a reminder of the enticing package he will be providing injuries can be kept at bay. He bowled three four-over spells in the match against Tasmania, removing Jordan Silk twice, and was getting the ball to carry through at good pace. His second-innings spell with the new ball was especially lively as he found the outside and inside edge of Charlie Wakim's bat in an over that somehow cost him 14 runs.

Shaun Marsh appears to be playing as well as ever. If it hadn't been for the search for quick runs to bring a declaration against Tasmania he could have had twin hundreds in the match and three in five innings this season. At 37 his Test career is surely behind him, although in this of all years it's probably wise to expect the unexpected. His first-innings 115 in the latest round, with Western Australia in trouble against a ball moving around, was a display of the highest quality. Across town, things did not go as well for another stalwart of Shield cricket: Callum Ferguson bagged a pair against Victoria, edging a wild drive against Will Sutherland in the first innings and nicking the new ball from Scott Boland in the second.

It was a sobering time for the Redbacks as Pucovski and Harris piled up the all-time Sheffield Shield partnership record of 486. On the second evening, when the score stood at 0 for 418, coach Jason Gillespie did not try to sugarcoat things and when they were 2 for 10 early in the second innings, facing a deficit of 354, defeat looked certain. However, in Travis Head they have an exceptional leader and batsman - for the second game running he led from the front to show that survival was possible with 151 off 296 balls. Still, he needed help and in 19-year-old Liam Scott he found it as the young allrounder added his name to the 'ones to watch' list as he took South Australia to the brink of the draw. The Redbacks have batted 288 overs across two second innings in their last two matches - to compete they must score first-innings runs, but they are a side that won't give in.