Hazlewood (side) and Marsh (adductor) came home early from the IPL with minor niggles and though both have since returned to bowling, and there remains confidence they'll be ready for the Ashes, the clash with India at The Oval on June 7 may come too soon.
Australia will effectively need to make a call by Sunday (May 28) when their 15-player squad for the final has to be submitted under the ICC rules for the final. Those traveling from outside the UK arrive on Saturday.
"We knew when he went to the IPL that everything would have to go perfectly on the back of the Achilles setback in India and this stage everything is good," Australia coach Andrew McDonald told SEN Radio. "But it will have to go perfect for him to be part of that World Test Championship final and available."
"We feel it's almost like a home summer. We usually pick four quicks and travel around and add players when we need. We've got Michael and Sean [Abbott] over there and feel they can be added in at any time depending on if new information comes to us."
Both Neser and Abbott will join the Australia squad when they reach London late next week and begin training following a bonding camp in the northwest of England.
Neser's omission from the original squad was the most debated call, but he and Abbott have had the benefit of playing competitive cricket in recent weeks. McDonald said that Neser's continued excellence did not surprise him and, perhaps significantly, made mention of his batting returns which have seen him average 38.66 since the start of the last Australia season.
"He's really pressing to be genuine allrounder, probably not a top six allrounder, but definitely a No. 7 or 8," McDonald said.
"You don't know how much to read into the information coming out around the injuries, how significant they are, but there is no doubt that they'll be having more conversations around where their injury list is at than we are," McDonald said. "It's always nice when you haven't got those moving parts and it's quite settled going in."
Cameron Green's format switch
McDonald acknowledged the quick turnaround between formats will be a test for Green. He found it tricky last season after the T20 World Cup, although in that case had had precious little batting time, and there were already signs he was adapting when he returned from his injury layoff during the Test series in India.
"The thing for me he's adaptable, he's a man for all conditions, he's always engaged in the game whether with bat, ball and in the field…he's high-end talent and is showing the world what he's got," McDonald said. "The challenge for Cam now is as he starts to become a three-format player is how he focuses [on] that, shifts between formats, and he's going to have another challenge in front of him going deep into the IPL finals to get ready for the World Test Championship match. So that will be a challenge for him, but he's a fast learner and every hurdle he's got over so far."
Glancing into the not-too-distant future, managing Green across three formats will become one of McDonald's key challenges.
"We've declared our hand with his entry into T20 cricket last year and now what's done in the IPL would suggest he's tracking to be a three-format player for us. Then it's finding the balance within all of that," he said. "You can't be everything to everyone and they'll be some series where he needs to be managed like all the other players when they play three formats. The demand's going to go up then clearly there's other leagues that will want access to him at certain times. It's going to be a bit of a juggling act but he's got a good head on his shoulders and we'll be able to work with him."
Andrew McGlashan is a deputy editor at ESPNcricinfo