NEIL Harris says he is "delighted" for his international contingent as he welcomes a trio of them back to Calmont Road.
Shane Ferguson, Jimmy Abdou and David Forde return to the club to prepare for Saturday's match at Crewe after a dramatic few days with their countries.
Mahlon Romeo is still away with Antigua and Barbuda as they defend a 1-0 first-leg lead in the third round of World Cup 2018 CONCACAF qualifying against Guatemala later today.
If they make it through they will enter a group containing Carlos Edwards' Trinidad and Tobago and the United States in the next stage.
Forde was again on the bench as Ireland won their second game in four days after beating Georgia 1-0 to strengthen their chances of qualifying for Euro 2016, while Abdou has returned following his involvement in Comoros' attempts to reach the finals of the 2017 Africa Cup of Nations.
Ferguson came off the bench for the second game in a row as Northern Ireland scored a crucial injury-time equaliser against Hungary that leaves them needing two points from their final two games to qualify for the European Championships for the first time in their history.
His return will give Harris a potential selection headache at the weekend, with captain Tony Craig having played at left-back for the last two league matches.
"Any of our players that can go and represent their country, I've said it before and I'll say it again, what a fantastic achievement, the pinnacle of your career," the Millwall boss said.
"I'm delighted that the boys have gone away. Jimmy played, Marlon came off the bench and Fordey's been a sub.
"Shane came on and got minutes, which is good, because obviously he was struggling with his hamstring. To be back in full training and get some competitive action is fantastic for us."
Steve Morison was on standby as Wales just failed to clinch early qualification for the tournament in France after a frustrating 0-0 draw with Israel, but they need just a point from their final two fixtures in Group B to confirm their place in their first major tournament since the 1958 World Cup.
And Harris believes his striker will be in contention for a place in Chris Coleman's finals squad once he finds goalscoring form for his club.
He said: "He'll be available for the next one if somebody is struggling and what we want is Steve Morison to be scoring bundles of goals for us, which he will do, and for him to force his way into their squad for the Euros as long as they get through.
"That would be a terrific achievement for him and for us as a club."
Meanwhile, Kyron Farrell came on as a second-half substitute as Ireland lost 2-1 to Italy in an U19 international friendly.