The Argentine did not feature in the club's 3-0 second-leg defeat in their UEFA Champions League semi-final against Bayern Munich due to a hamstring injury he sustained in the first leg of the quarter-final with Paris Saint-Germain.

Tito Vilanova's men have received much criticism in recent weeks for their performances while Messi has not been fully fit. The Camp Nou outfit were held to a 1-1 home draw by PSG and were hammered 7-0 on aggregate by Bayern, with the current FIFA Balon d'Or holder very much a peripheral figure. 
However, the 25-year-old is set to return, as Barcelona prepare to try and secure their 22nd Spanish title.
A statement on the club's official website read: "Leo Messi and Sergio Busquets, who had not been able to work at the same pace as their team mates in recent sessions, trained normally."
The Catalan club could be without goalkeeper Victor Valdes for the visit of Betis, while Pedro is also a doubt due to illness.
Vilanova's side have an 11-point lead over Real Madrid at the top of La Liga and will secure the domestic crown if they overcome Pepe Mel's team and Madrid fail to beat Real Valladolid. 
Messi has made 48 appearances in all competitions this season, scoring 58 goals.