Mathis may need just three more rehab games, and could be activated as early as Monday, according to MLB.com.
Upon his return, Mathis will likely be the backup option to J.T. Realmuto.
"He's a big presence in our clubhouse," Miami manager Dan Jennings said.
Crawford is ranked the 14th best prospect in the game by Baseball America.
The right-hander, who has experienced back and shoulder pain this season, will be evaluated on Saturday before the team makes any decision, according to MLB.com. His next start, tentatively scheduled for Wednesday, is very much up in the air at this point.
Frazier has 13 hits in 38 at-bats over his last 10 games, including three home runs. He has been held hitless just once over that stretch.
The home run was his only hit of the game. It was his eighth longball of the season, but his first since April 28. He now sports a .275 batting average on the season.
Jordan (0-1), who entered the game in the second inning, tossed 4 2/3 innings, allowing three runs on six hits while walking two. He struck out one batter on the evening.
Jordan, who was recalled from Triple-A on Sunday, was making his season debut for the Nationals on Friday. He owns a 2.14 ERA over 42 innings in seven starts for Triple-A Syracuse this season.
Chapman has been shaky recently, giving up earned runs in two of his last four outings. But he is still a perfect 8-for-8 in save chances this season.
He gave up RBI-singles in the fifth and sixth innings accounting for all the damage against him, as he was able to quiet a dangerous Nationals offense. DeSclafani will make his next start on Thursday in Philadelphia.
Axford, who came in with the Rockies up 4-0, allowed an unearned run to score with one out, thanks to an error by left fielder Brandon Barnes. But Axford was able to get the next two batters out to close out the game.
The unearned run ends a seven-game scoreless streak for Axford, who still holds a very fine 0.69 ERA on the season.