Reading winger Modou Barrow looks set to miss the Carabao Cup clash with former club Swansea.
The Gambia international was forced to sit out the weekend draw with Brentford after picking up a knee injury and is unlikely to be fit to face the Premier League side on Tuesday evening.
Royals defender Jordan Obita came off the bench at the weekend and is in contention to start following an ankle injury, but the third-round cup tie could come too soon for midfielder John Swift who has returned to training following a hamstring problem.
Striker Yann Kermorgant (hip/groin) and long-term absentee Callum Harriott (knee ligament) remain out.
Swans boss Paul Clement is likely to make changes for the trip to Reading, but not wholesale switches, with Sanches, Angel Rangel, Leroy Fer and Roque Mesa all probable starters, along with striker Wilfried Bony.
Swansea head back along the M4 three days after holding Spurs to a 0-0 draw at Wembley.
And Mawson, asked if the Swans required a reaction following their home defeat against Newcastle six days earlier, added: "Yes, especially the performance.
"We didn't do enough last week, and we knew it would be a tough game, but we seem to come away to the big grounds, like we did season, and prove that we are a good side."
Swansea are unbeaten in four games on the road this season in all competitions, conceding just one goal away from home, and Clement said: "Good defending has to be applauded.
"You go to Italy and they applaud it. We are showing that on our day we are difficult to beat."