Andy Carroll scored his second goal of the season in West Hamâ€™s 1-0 win over Swansea on Saturday.
The 24-year-old is currently on loan at Upton Park from Liverpool but the beginning of his West Ham career has been blighted by hamstring and knee injuries.
"Coming into a new team and getting injured in my first game to put me out for six weeks was frustrating," he told West Ham's official website.
"Then I was back for a couple of games and was out for eight weeks. It's hard when you're injured anyway, but when it's at a new club it's even harder.
"I've kept my head up as much as possible and worked hard with the physios and fitness coaches to get back and I showed on Saturday that I am fit."
Carroll praised the club's medical team for getting him back to fitness in time to make a match-winning start against Swansea as the Hammers claimed only their second Barclays Premier League win in 10 games.
He said: "I've been keeping fit in the gym and all the backroom staff have been helping me. The fitness coaches and physios have been on me, working me hard.
"When I couldn't run I was in the gym and the hard work paid off with 90 minutes on Saturday.
"I didn't find out until the day of the game that I was going to start and obviously I was over the moon with the decision. I just had to work hard, run around and keep the ball as much as I could.
"It was a tough game and I'm just happy that we got the three points."