Scotland play Nations League games against Slovenia (twice), Switzerland and North Macedonia during the first international window of the season.
There is better news for Swansea regarding skipper Ben Cabango, who came off with a heel problem during the Blades draw.
He sat out the Derby and Watford games but Matos says the centre-back has a chance of returning to face Wrexham.
Such is Swansea’s form, however, there is no guarantee that Cabango will immediately return to the starting side.
Matos’ team top the Championship having taken 10 points from their first four league games of the season.
They boast the best defensive record in the second tier having conceded only once, at Stoke City on the opening day, so far in the league.