If you are going to use Roman numerals for the small numbers, then you have to use them for the big numbers too. Your sentence should read as follows:
"Hoyer was an undrafted free agent out of Michigan State (where he was Honrable Mention All-Big Ten in MMVII). He appeared in XIII games for the Patriots from MMIX to MMXI, and was XXVII of XLIII for CCLXXXVI yards, I TD, and I INT."
Would have been perfect if you had mentioned that he played in the Big X conference.
“We'll do the same thing that we always do. We'll take every situation from week to week and do what we think is best for that week and evaluate it on that basis.” - Bill Belichick