After undergoing intensive rehabilitation work, the forward hopes to spend less time in the treatment room going forward.He said: “I’m feeling really good, it’s been a difficult couple of months for me but my fitness has came right back.“I need a run of games to get back to my best but the only way I do that is by working hard in training and catching the manager’s eye.“It’s going to be difficult, since I’ve been out Moussa and Odsonne have been doing really well but when I get the chance I need to take it. “Celtic were very accommodating in letting me go to see this guy, it’s went really well and hopefully I’ve found the cause of the problem and it’s behind me.He added: “It’s both calves, after the assessment he identified where the problem was coming from so that’s what we worked on.“I’ve got a tear in my calf muscle but the problem wasn’t coming from there, it was coming from my hips.“My glutes are that tight that my hamstrings and calves were doing double the workload they should have been.“That was the be all and end all. It’s a huge relief and a weight off my shoulders, I can just concentrate on my football now.”Griffiths missed Alex McLeish’s first two games back as Scotland boss as he rebuilt his fitness.The talisman of the Scots’ last qualifying campaign insists he is desperate to be involved in the upcoming friendlies in Mexico and Peru, and envisages Brendan Rodgers will have no problem with it.He added: “You always want to be involved in internationals, there is another couple of good friendlies at the end of the season that I’m trying to be involved in. “Definitely, they are exciting games. Pulling on the national jersey means everything to me.“I don’t see why it would be a problem, I’ve missed a lot of game time but the friendlies at the end of the season will be competitive and can stand me in good stead going into pre-season. Celtic striker Leigh Griffiths believes his injury nightmare is behind him after visiting a specialist down south and says he’s ready to star for club and country in the coming months.The 27-year-old ended a two-month stint on the sidelines when he returned to action for the Hoops as a substitute in the 3-0 win over Ross County.A persistent issue with his calves flared during Celtic’s January win over Griffiths’ former club Hibs, leaving the Scotland international to look far and wide for a solution to his ongoing fitness problems.Celtic granted Griffiths permission to visit a specialist in London and Manchester as he looked to uncover the cause of his ongoing calf pain.