Rangers have offered a contract to Rennes defender Mexer and he could watch them against Celtic this weekend, STV has learned.

The 30-year-old defender is out of contract at the end of this season and has been pinpointed as the man to strengthen Rangers' back line.

Rangers manager Steven Gerrard flew out to France to meet the player and he has been offered a deal at Ibrox next season. And the Mozambique international has been invited to take in the derby this weekend as he mulls over his options.

Mexer, who was previously with Sporting and Nacional, has impressed with Rennes this season and scored his side's second goal against PSG as they won the Coupe de France this season.

If the centre back accepts Rangers' offer, he would become Gerrard's fourth signing for next season. Jordan Jones, Jake Hastie and Steven Davis have all signed pre-contract agreements with the club.