Although I understand the point you are making over the scale of their achievements at a different level,you should modify the above to:
the difference in quality between someone who [does quite well] has been outstanding in League 1, and someone who [has done well] once was quite average at international level,the last time probably 6 years ago.
If its Vassell we are talking of then his best days are behind him,and isn't he now injury prone?