Jason Lewry steps up his recovery after a month out through injury today.
But the Sussex fast bowler will have to wait another three weeks before he is able to rejoin the county's bid for their first Championship title.
The left-armer, whose contract expires at the end of the season, tore a rib muscle against Leicestershire on July 15.
Lewry has had three gentle run outs this week and will step up his recovery with a more rigorous net session prior to the start of today's play in the Championship game against Lancashire.
He has tentatively pencilled in the second team fixture against Kent at Eastbourne on August 27 for his competitive comeback.
He said: "I had a run through for the first time earlier this week and it was sore afterwards, but I'm going to have a proper bowl in the middle today.
"I would have been quite happy to have had an injection and get back sooner, but (physio) Stuart Osborne doesn't want me to risk it.
"I had pencilled in the second team game against Surrey next week, but that will probably be too early.
"All being well I can play the following week and then be available for the Championship match against Middlesex on September 5."
With Lewry still absent and James Kirtley likely to retain his place in the England team for next week's fourth Test at Headingley, the county's hopes of overhauling leaders Surrey rest largely on the shoulders of Mushtaq Ahmed.
It is a challenge the leg spinner is clearly relishing. He took his tally of Championship wickets to 75 with four Lancashire victims on a compelling day in the battle between second and third at Hove yesterday.
Stuart Law, who fell four runs short of completing a third successive hundred against Sussex, and Carl Hooper were among his victims before Lancashire reached 351-8, still 34 behind, to leave the contest evenly poised going into the last two days.
With Surrey stretching their lead at the top to 20 points after completing victory over Nottinghamshire inside three days, a draw is not much use to either of their closest challengers.
After he was criticised for being too cautious when the Surrey match ended in stalemate, Sussex skipper Chris Adams will have to time any declaration well, assuming his team-mates can put him in the position to dictate terms when they bat again.
The ace up his sleeve is undoubtedly Mushtaq who will fancy of chances of even richer pickings on a wearing fourth day pitch. There was some slow turn to assist him yesterday, but as usual it was his variety which kept the batsmen guessing, particularly when he deliberately pushed his leg spinner through quicker.
He broke through before lunch when Iain Sutcliffe was snapped up at silly point after putting on 99 for the first wicket with Mark Chilton.
After coming to terms with the slow surface, Law moved effortlessly through the gears during the afternoon and when Hooper joined him, after Chilton had top-edged a paddle sweep off Mark Davis, everyone in another good crowd sensed the match had reached a critical stage.
There was time for Hooper to hit four sublime boundaries but the Australian-West Indian axis was broken after just 23 minutes when Mushtaq took a return catch at the second attempt as Hooper got a leading edge aiming to deposit him over mid-wicket.
Chris Schofield lost his leg stump in Mushtaq's next over and at 192-5 there was suddenly the prospect that Lancashire might have to follow on.
But Glenn Chapple, who has made two Championship centuries this season, overcame a shaky start to help Law put on 97 in 34 overs for the sixth wicket. Like everyone else, Law had his problems picking Mushtaq but he dealt ruthlessly with the slightest indiscretion in line or length by the Sussex bowlers, particularly when he pulling anything short with brutal power and sublime timing in the area between mid-wicket and mid on.
Another century against Sussex seemed to be his for the taking so it was a surprise, not least to Law himself, when he offered a bat-pad catch to short leg to give Mushtaq his fourth success after facing 162 balls and hitting 11 of them to the boundary.
The day wasn't all about Mushtaq or Law for that matter. Billy Taylor bowled with sustained hostility at the start and later with the second new ball to take three wickets including Chapple after he'd made a vigilant 54.
By the close Mushtaq had bowled 43 overs, but his workload is likely to be even greater this weekend.
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