Fletcher has not featured for his country since informing the SFA by text message that he did not wish to be selected for a game against Northern Ireland in February 2011.
But the 25-year-old, who has scored five Barclays Premier League goals for Sunderland in just four appearances, returns after holding clear-the-air talks with Scotland boss Craig Levein yesterday.
Manchester United midfielder Darren Fletcher was also included in the squad, making his comeback after a lengthy spell on the sidelines with a chronic bowel condition.
Fletcher's dramatic return to the Scotland fold came after he told Levein he was desperate to play for the national team again, ending months of international exile.
The stand-off between player and manager was broken by Fletcher last month, when he indicated on Twitter that he was keen to return to play again.
Levein today described the player's return as a "no-brainer" following the involvement of an un-named third party.
He said: "It's a big plus for me and the rest of the team for him to be involved. I got a phone call through a third party during the week and that was an indication from that person that Steven was desperate to come back and play.
"Things progressed between myself, this third party, his agent and the boy himself. I got a text saying he was willing to have a chat about it so I called him last night and, as he said to that person, he was desperate to come back and play. For me, then, it's a no-brainer."
Both men are set to meet face to face this week, with Levein adding: "We went through a number of things and I plan on making an appointment for us to see each other later this week as well so we will go into it a little bit further then."
Fletcher has been in fine form, scoring five goals in his last four outings for Sunderland, while the Scots endured a stuttering start to their campaign with two points from home games against Serbia and Macedonia.
However, Levein refused to dwell on what might have been had the situation been resolved sooner.
He said: "The longer I thought about it, I thought we were in a situation where nobody was winning. So I bit the bullet, phoned him and had a chat and everything is resolved.
"Things happen and there is no point in looking back on what might have been. Steven has indicated his willingness to play, we have resolved any issues we had and he will be in the squad the same as everybody else now."
Levein has also been handed a major boost with the return of Fletcher following a chronic bowel complaint, as well as Celtic skipper Scott Brown from injury.
The manager said: "Looking at the list of players, Steven Fletcher is back, our captain Darren Fletcher is back and I've got Scott Brown, probably one of our most influential players, back as well. So it's a good day for me."
However, there was still no place in the squad for Kris Commons, who has impressed for Celtic this season.
Levein said: "He's been really unlucky because he's playing exceptionally well. But it's one of the strongest areas of my team.
"He just needs to keep the form he's in just now and hopefully he will be in the squad sooner rather than later."
The full squad for the World Cup qualifiers against Wales on October 12 and Belgium on October 16 is: Adam (Stoke), Berra (Wolves), Brown (Celtic), Caldwell (Wigan), D Fletcher (Man Utd), S Fletcher (Sunderland), Forrest (Celtic), Fox (Southampton), Gilks (Blackpool), Hanley (Blackburn), Hutton (Aston Villa), McArthur (Wigan), McGregor (Besiktas), Mackie (QPR), Maloney (Wigan), Marshall (Cardiff), Martin (Norwich), Miller (Vancouver Whitecaps),Morrison (West Brom), Mulgrew (Celtic), Naismith (Everton), Phillips (Blackpool), Rhodes (Blackburn), Snodgrass (Norwich), Webster (Hearts).
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