Having selected only 21 players Brown had a place to fill in the party - and McCoist was swiftly invited on Sunday night, such is Brown's concern at his shortage of firepower.
Now there is the real prospect of McCoist joining Kevin Gallacher from the outset in Vilnius with Brown tempted to opt for the in-form veteran with 59 caps and 19 international goals to his name.
The national coach said: "I expect Lithuania to defend deep, much as Hearts did on Sunday, and to my mind that will suit Ally's game. I would honestly say he is as good, if not better, than those other players under consideration for the front role."
With McCoist's former Ibrox colleague Gordon Durie ruled out because of ankle ligament damage, McCoist has few rivals in attack.
Brown rates the Lithuanians highly, suggesting they are the best of the Baltic states, and, by his own admission, McCoist could prove the "quick fix" he needs to do the job required.
Brown followed the inclusion of McCoist with a further change yesterday, this time forced upon him because of injuries.
Blackburn's Billy McKinlay and David Hopkin, of Leeds, have withdrawn from the travelling group because of fitness problems. That has prompted Brown to promote Rangers' 20-year-old midfielder Barry Ferguson from the Under-21 squad.
Ferguson was instrumental in Rangers' emphatic 4-0 win against St Johnstone on Saturday. Brown said: "Barry was very close to being selected in the original squad, although I didn't think he would start the game as we had experienced provision in McKinlay and Hopkin.
"The Under-21 team have a difficult game and obviously want to qualify, so their coach, Tommy Craig, will be tearing his hair out at losing Barry."Reuse content