Wales began at the end of last week’s victory over Dodid, but was an unused substitute in Wednesday’s defeat to Mazerwell.
Kelly comes out this season when they play the heart in the Scotland Premier League, and they have ninth place in Scotland’s first trip to Scotland.
Wales have scored 12 goals in 24 appearances in 24 appearances for Allloa on loan last season.
Welsh is an international player of Scotland who has won the top award in Kilmarnok in the backward season.
In March, Kilmarnok coach Derrick McCains said he would be “destroyed” if he left Wales, but he is scheduled to leave this summer to take over in his hearts.
“Bobi is a talented young player, and someone who is proud of the experience of high football,” said Swansea Montag.
“We believe he has the ability to grow for an important player for Swansea City, and his personal praise has been emphasized in recent years.
“We are happily waiting for Swansea to welcome Swansea at the beginning of the season, and we are very happy that we have been able to take a decisive step to achieve another in the new campaign.
Wales is the second deal to have agreed since the end of the tournament at the end of this month.