The Japan international says he must make more of the chances he is being given at Old Trafford after being substituted at half-time against West Brom
The Japan international was afforded a rare start against West Brom on Saturday but was substituted at half-time as the champions crashed to a shock 3-1 defeat.
Kagawa has made just four appearances for David Moyes’s men this season and readily admits he must improve if he is to stay at the club.
"I have to understand the message I was given [by being substituted] and play better," he told Japanese newspaper The Hochi Simbun.
"There's a long road ahead. But if I don't take advantage of chances like this, I won't be able to survive here. I have to stay positive and play hard."
The 24-year-old also claimed the substitution was purely tactical but admitted he had endured a quiet first half against Steve Clarke’s side.
"I wasn't injured and I didn't think my finishing was that bad. It's true that I didn't see the ball very much," he added.
"I thought there would definitely be space [for me to create chances] in the second half, so in the first half I was trying to play patiently."