However, since he slotted into the side, Town have not lost and Jimmy Quinn has admitted talking to the League One side about an extension of the deal.
He told the Shropshire Star: 'I will be having a word with Dave Penney and I spoke to him about it [the extension] on Monday as well'.
McGrath's initial deal allows him to play in the next two games, against Yeovil and Bournemouth, but Town fans will surely be hoping that the stay is a longer one.
Meanwhile, trialist and former Real Madrid player Pedro Matias will play in the reserves for the third time tonight, with no indication yet as to whether he will get a permanent deal.