Brown missed the Champions League Group G win over Barcelona on Wednesday night with illness and has not recovered yet. Right-back Mikael Lustig should recover from a hip knock but left-back Emilio Izaguirre (hamstring), stopper Thomas Rogne (calf), winger James Forrest (hamstring), and strikers Gary Hooper (hamstring) and Lassad (groin) are all still out.
St Johnstone's Callum Davidson and Paddy Cregg are nearing returns, but Sunday's clash may come too soon. Davidson played for the under-20s side in midweek after a back problem, while Cregg returned to training this week following a hamstring injury. Winger Peter Pawlett (hamstring) is also close to match action, but Craig Beattie (thigh) and Jamie Adams (back) are likely to be absent once again.
Hibernian v Dundee United (Sunday, 12.45pm)
Defender Tim Clancy is unlikely to be fit as Hibernian take on Dundee United on Sunday. The right-back has been troubled by a groin injury and missed the Clydesdale Bank Premier League with victory over St Mirren last Saturday. Alan Maybury is again likely to play in place of his fellow Irishman, while midfielder Gary Deegan (fractured jaw) remains out.
Dundee United defender Barry Douglas will miss the clash with Hibernian. Douglas is out with an ankle injury after missing the 1-0 win over Motherwell because of a knock he picked up in the 2-2 draw with Celtic a few days earlier, so Brian McLean is set to continue in defence. French defender Gregory Vignal is still sidelined after his recent hamstring tear.
Saturday's fixtures (3pm)
Inverness v Hearts
Inverness midfielder Ross Draper will miss his side's SPL clash with Hearts at the Tulloch Caledonian Stadium. The Caley man twisted his ankle near the end of the win over Kilmarnock at Rugby Park last week and is not yet ready to return. Long-term absentees Simon King (ankle), Chris Hogg (knee) and Nick Ross (shoulder) are still out.
Hearts midfielder Ryan Stevenson will return for the Clydesdale Bank Premier League clash at Inverness after missing last weekend's defeat by Dundee with concussion. Scotland Under-21 goalkeeper Mark Ridgers and right-back Jamie Hamill are still unavailable following knee injuries. Dale Carrick remains on the sidelines following hernia surgery while Darren Barr's red card in the cup at Tannadice will not affect his SPL eligibility.
Kilmarnock v Ross County
Killie had their appeal against Bell's dismissal for denying a goalscoring opportunity upheld by a Scottish Football Association panel on Thursday. Kenny Shiels still has William Gros, Garry Hay and Danny Racchi on the sidelines.
Ross County are still without midfielders Paul Lawson and Russell Duncan for the Scottish Premier League clash at Kilmarnock. Lawson has a hamstring injury while Duncan is still short of fitness following injury. Mark Corcoran is back in training following a groin problem but is not likely to feature.
Motherwell v Dundee
Motherwell defender Shaun Hutchinson will have a late fitness test ahead of the Scottish Premier League clash with Dundee. Hutchinson has missed two games with a hamstring injury and will not be rushed back if there is any problem. Fellow centre-back Fraser Kerr is back in the squad after a calf knock leaving Steven Saunders (knee) as the only definite absentee.
Dundee skipper Stephen O'Donnell is absent as he recovers from a hamstring injury. Brian Easton (hamstring), Mark Kerr (knee), Davide Grassi (knee), Carl Finnigan (knee) and Jamie McCluskey (Achilles) are all out.
St Mirren v Aberdeen
St Mirren will be without suspended skipper Jim Goodwin for the visit of Aberdeen in the Clydesdale Bank Premier League. Goodwin sits out the clash in Paisley following his red card in last week's defeat to Hibernian. Long-term absentees Paul McGowan and Darren McGregor remain on the sidelines.
Aberdeen midfielder Stephen Hughes will miss two weeks or so with an ankle injury, according to manager Craig Brown. Several first-teamers also suffered knocks and strains in training, with Brown waiting on Gavin Rae, Ryan Fraser and Gary Naismith. Good news is the return of striker Rory Fallon from injury.