The 20-year-old midfielder started the 2-1 William Hill Scottish Cup defeat at the hands of Aberdeen on December 11 but after completing the full 90 minutes suffered some discomfort to the knee.
Carswell then underwent a scan which revealed he was suffering from tendonitis and following 10 days of rest he was able to come off the bench for the Steelmen's successful revenge mission on the Dons on Boxing Day which came in a 4-1 SPL victory at Fir Park.
After he failed to get off the bench at Celtic Park in the narrow January 2 loss to the SPL champions, Carswell says he has benefited from the extra rest and is ready to ramp up his bid to make a place in the Motherwell midfield his own.
The Fir Park fledgling said: "The problem with the knee was a frustrating one as it was great to get in and get the full game against Aberdeen but I knew the knee wasn't right. Afterwards the scan revealed a slight problem with tendonitis and to be honest that was a relief.
"I then had 10 days of rest and got on off the bench in the Boxing Day game with Aberdeen and obviously didn't feature against Celtic, but if anything all of that has been a help in clearing up the problem.
"We came back for training on Friday and again on Saturday so we are already well into preparations for the St Johnstone game on Sunday and to be honest I feel great.
"So for me I just want to have the best week I can in training and really try and do everything I can to persuade the manager to include me in his plans for the weekend."
Motherwell's only signing during the transfer window has been 23-year-old Kallum Higginbotham on loan from Huddersfield Town until the end of the season.
Carswell admits he has already been impressed with the versatile former Falkirk star.
He said: "Kallum has looked really good since he has been in training with us. He has been in working with us for a couple of weeks and it is obvious that he can play in a variety of positions. With Jamie Murphy having gone it is great that the gaffer has managed to sign up someone of Kallum's quality who can play in virtually all of the places middle to front.
"The bottom line is that you don't sign for a Championship side like Huddersfield if you are not good quality. So it is great for us that we have managed to get him until the end of the season otherwise there would have been a bit of a hole with Jamie gone."
Looking forward to the visit of St Johnstone on Sunday, Carswell admits it is the perfect opportunity to try and do something about the erratic home form that blighted the first-half of the campaign for Well.
The Well starlet said: "We know that our home form results were not good enough but the frustrating thing was we felt like we didn't get the points on the board we deserved from our home games in the first half.
"We have yet to lose to St Johnstone after two games already with them this season. They'll be one of our rivals for a European place and are just four points behind us in the SPL. So it is vital we make the most of home advantage."