IT will be a “proud achievement” for centre Ryan Mills as he makes his 100th appearance for Worcester Warriors by leading the side out in the European Challenge Cup at Castres on Saturday (1pm GMT).

The versatile Mills, 27, joined from Gloucester in 2014 after an injury-hit spell and made his debut against Moseley in the British and Irish Cup in October that year.

He will be the 23rd player to get to the ton for Warriors in the professional era and will captain the team having recovered from a shoulder injury that ruled him out of the Gallagher Premiership win at Harlequins two weeks ago.

Worcester field a much-changed but experienced line-up in France as they look to build on the 57-14 victory over Enisei-STM in Russia last weekend.

Full-back Chris Pennell and fly-half Duncan Weir also return to the first XV with prop Nick Schonert and scrum-half Francois Hougaard on the bench after all four recovered from injuries.

Mills said of reaching the landmark: “It’s something I’m pretty happy about considering the amount of time I spent out injured in the past before I came to Worcester.

“It’s quite an achievement for me so I’m pretty proud of that.

“It shows loyalty from the club and player on both sides to be around that long to hit those achievements.

“When we have got people like Jonny (Arr) in the past and Penns (Chris Pennell) to look up to who are hitting that 200 mark, that’s something we are chasing after and a goal you set yourself.

“But the injuries make it really difficult to hit those kinds of targets. When you factor that in with the increased physicality and intensity of the game it does make the achievement something you are quite proud of.”

Mills reflected on his time at Sixways and admitted: “The club has changed a lot since I first came here.

“We are still gradually heading in the right direction.

“It does take time to break old habits but we are making inroads into it and our squad depth this season is arguably probably the best we’ve had.

“We lost a couple of big players from last season that we’d loved to have kept. But we’ve recruited well and replaced them well.

“If you look at the Harlequins game where we beat them away, we managed to make a few changes, rest a few players and rotate the side.

“The boys took their opportunities and played extremely well which is another nod towards the depth of squad we have got.

“Injuries do happen more often these days so the squad depth is really important and everybody has to be ready to take their chance. We have huge confidence in players throughout the whole squad.

“Being able to go away to Russia, which is a banana skin with the travelling, and getting a win with such a young side shows the potential we have for the future years down the line as well.

“The young guys are ambitious and want to take your spot now which is fantastic.

“For us, it’s about helping and mentoring them so that in the years to come they are ready and can become the number one and then we don’t have to look elsewhere which adds to the sustainability of the club.”

Mills expects a stern test from Castres and said: “They lost away last week to Dragons (31-17) and will be pretty frustrated off the back of that.

“We will be facing a big challenge. They are a big, physical side. We know French sides at home put out strong teams. They will be coming out all guns blazing.

“It will stand us in good stead for Sale the following weekend as they are a physical side as well. It’s about performing in Castres to take away some positives for the next week in the Premiership.”

Versatile back Jamie Shillcock will make his 50th appearance for Warriors if he comes off the bench in Castres.

Former Blues hooker Matt Moulds is in line to make his Worcester debut as a replacement having recovered from a pre-season knee injury that required surgery.

Warriors: Pennell; Humphreys, Venter, Mills, Fidow; Weir, Heaney; Waller, Annett, Carey, Bresler, G Kitchener, Hill, Lewis, du Preez. Replacements: Moulds, Black, Schonert, Clegg, van Velze, Hougaard, Lawrence, Shillcock.

Castres: Palis; Nakosi, Combezou, Ebersohn, Paris; Urdapilleta, Kockott; Gerondeau, Tulou, Delaporte, Capo Ortega, Samson, Wihongi, Rallier, Tichit. Replacements: Jenneker, Fa’anunu, Hounkpatin, Gimeno, Vaipulu, Fernandez, Batlle, Dumora.