James Anderson says he will have to come through England's three-day warm-up match against South Africa A on Friday if he has any chance of being fit for the first Test at Centurion on Boxing Day.
Anderson, who pulled up with a calf injury four overs into what proved to be his only spell of last summer's Ashes series, played his first competitive game since a Lancashire Second XI fixture at the end of August earlier this week, taking 1 for 37 in his 11 overs against a Cricket South Africa invitational side at Benoni.
And he admitted that he felt short of match practice, and was some way short of his top speed during his return to action.
"It feels like a long time since I played a competitive game," Anderson said, "so to get back out in the middle and get some overs under my belt is very pleasing. There was a bit of rust there this morning, but that's to be expected not having played for four or five months.
"A six and a five[-over spell] was pretty good, with an eye on potentially playing at the end of the week and getting more overs in then. It was a good start: I felt better second spell, bowled a bit better, and felt like things were coming together. At the same time, I know I'm not up to max speed yet, so that's something I've got to try and get better at by the end of the week."
England were short of three frontline bowlers in Stuart Broad, Jofra Archer and Jack Leach, all of whom went down ill on Wednesday, and as a result, Anderson is expected to get a good opportunity to prove his fitness ahead of the first Test.
The match was to have been Anderson's first first-class game since his injury at Edgbaston this summer, against a strong South Africa A team which features Temba Bavuma, Reeza Hendricks and Theunis de Bruyn. However, the match has been downgraded to a friendly to allow the ill players a chance to recover and still take part.
"We've got a few men down with illness and that, so it might not be such a difficult team to pick," Anderson said, "but I'd like to be in that. If I've got any chance of being in that first Test, I think I need to play that three-day game.
"To be honest, I'm just trying to force my way back into the side - that's all I'm thinking about. I'm just hopeful that I can get my fitness up to speed [and] be bowling well enough that I can get picked for that first Test.
Before the game was downgraded, Anderson suggested that its first-class status would help to replicate the "intensity" of an international game. "It's really good to have that first-class [game] just before a Test series," he said. "It's good to create that intensity that you need, there's a bit more on it... it means that bit more, so it's good for us to have that intensity ahead of what is going to be an intense four-Test series."
There have been no targets set by the England set-up regarding how many games Anderson can hope to play in the series, and he suggested that the pace-bowling camp he was part of in Potchefstroom has given him the confidence to "hit the ground running".
"It was just [about] getting some more overs in and really trying to build up my rehab," Anderson said, "build up my confidence as well, and feel like I can step up the gas, bowl with a bit more confidence and freedom. It was really helpful for me - I feel acclimatised now. I felt like I could come into this game and not feel I had to ease my way in, I could just hit the ground running.
"I've bowled in the nets and I've bowled in the middle as well in the last two weeks out here against a couple of our lads, [but] you just can't recreate that match intensity. I think I was a little bit off the pace in my first six overs, and it felt a lot better in the second spell. I'm sure that going into the next game, if I do play the next three-day game, then spell after spell, that'll hopefully just keep getting better and better."
England's seamers struggled in Anderson's absence in New Zealand, toiling fruitlessly on their way to a 1-0 series defeat. But Anderson suggested that South African pitches should be provide more assistance for their attack.
"New Zealand's always a hard place to go when there's not much swing, and the pitches are pretty flat there," he said. "I think here, you get a bit more - both in the wicket and, with the ball, you get a bit more through the air.
"It's still not a huge amount of swing, or for a long period of time, so it's about being spot on for that period that it does swing for - you've got to be right on the money."