Rossiter was expected to be back for Sunday's Betfred Cup semi-final with Celtic but Mark Warburton confirmed the midfielder is still working with the Gers physios while Wilson is progressing after tearing a thigh muscle but is not quite ready for action.
The Ibrox side are still waiting for official confirmation on how long playmaker Niko Kranjcar will be sidelined for after injuring his knee in training.
St Johnstone came through their derby win over Dundee unscathed.
Tam Scobbie is close to a comeback but is unlikely to feature at Ibrox, while fellow defenders Keith Watson (thigh) and Ally Gilchrist (groin) are making good progress but remain sidelined.
Team News – Rangers
After a derby day hammering at Celtic Park earlier this season, Rangers were expected to suffer the same fate when meeting Celtic at the national stadium on Sunday. What they got was another defeat, and an end to their latest bid for silverware, but the performance was a marked improvement and gave The Bears something to work with.
Making a list of changes to his usual approach, Rangers manager Mark Warburton saw his light blues go down in horrible fashion, losing to an 87th-minute Dembele goal, with the match seemingly heading for extra-time. It had been a brave effort prior to losing that goal with stand-in goalkeeper Matt Gilks receiving a man-of-the-match award for a heroic performance, but Rangers did have chances of their own, mostly on the counter-attack. Fans were left devastated by the result but positives can be taken and that must be used as a starting point for further improvement.
Warburton chose to concentrate on the plus points in his post-match interview, saying his hard-working side answered their critics in proving the gap between his side and the current champions is not as big as many thought before kick-off. He put on emphasis on self-belief in the squad and says that is improving as his men begin to do their talking on the pitch.
The Govan side have won each of their last two league starts, against Partick Thistle and Inverness, both without conceding a goal, and a 1-0 defeat to Celtic suggests the previously under-fire defence is making fast improvement. Getting back to winning ways at the first time of asking would go some way to healing the hurt of fans and the home win has been priced as 8/13 favourite with Coral, which is the best price around. Rangers to win to nil again is 7/4 (Paddy Power).
Team News – St Johnstone
St Johnstone beat Dundee on Sunday to move up into fourth-place, a point behind Aberdeen in second, although they have played a game more than most of the sides around them. That means Tommy Wright’s club have lost just one of their last six, a surprise 1-0 reverse to Kilmarnock.
The Saints secured a 2-1 win over Dundee last time but the manner of victory was a lot more comfortable than the final score suggests with Anderson and Swanson scoring second-half goals before Loy needed a penalty in the closing stages to give the scoreline a bit of respectability.
St Johnstone fans will remember their last trip to Ibrox fondly, running out 3-1 winners in a League Cup fixture last year thanks to goals from Murray Davidson, Simon Lappin and Michael O’Halloran, with the latter now on the books of Rangers. The Saints getting a repeat performance is 55/1 with Bet Victor in the correct score market while three points by any score is 9/2 with Coral. A draw can be had at 3/1 with the same firm.
Head To Head
Rangers have won four, drawn one, and lost one of their last six meetings with St Johnstone.
Rangers vs St Johnstone Stats
St Johnstone have lost just 20% of their away days in the Scottish Premiership this season, whilst Rangers have won 44% of their league games.
Rangers Team News
Rangers have no injury concerns, but the controversy surrounding Joey Barton continues so he won't be playing on Wednesday.
St Johnstone Team News
Right back Keith Watson and centre back Tam Scobbie are still a week or two away from a return.