LONDON, England – Logistics were a major focus for the Jaguars Thursday and Friday.

And as Head Coach Gus Bradley saw it, the annual trip across the Atlantic went well, with the Jaguars liking their late-week approach to arriving for the International Series.

A pressing issue now:

The health of running back T.J. Yeldon, who entering the weekend remains an unknown for a team that at last is getting healthier after an injury-plagued start to the 2015 regular season.

Yeldon, a rookie and the Jaguars' leading rusher, was listed as questionable on the team's final injury report of the week Friday. He missed last Sunday's game with a groin injury, but practiced limited Thursday before the team left Jacksonville for London.

He was listed as working limited for a light walkthrough at Allianz Field in London Friday.

"He got some more reps today, so we'll keep checking on him," Bradley said Friday as the Jaguars (1-5) prepared to play the Buffalo Bills (3-3) at Wembley Stadium Sunday at 9:30 a.m. ET.

"We evaluate his level and where he's at physically after every practice, so hopefully we'll know more (Friday night)."

Tight end Clay Harbor, who did not practice Thursday or Friday because of an abdomen injury, also was listed as questionable, with safety James Sample (shoulder) listed as doubtful. Sample has missed the last two games with the injury.

Listed as probable for the Jaguars:

Defensive end Chris Clemons (not injury related), safety Johnathan Cyprien (calf), wide receiver Allen Hurns (ankle/thigh), defensive tackle Sen'Derrick Marks (knee), offensive tackle Jermey Parnell (knee), wide receiver Allen Robinson (lower leg) and tight end Julius Thomas (chest/hand).

Bradley said Hurns and Robinson, the team's two leading receivers, have taken more repetitions in practice as the week has continued. Bradley said he is optimistic the two will play Sunday.

Marks, who missed the first five games of the season rehabilitating after January reconstructive surgery on his right knee, was limited Thursday with a knee contusion on his left knee.

"He seemed to be feeling a lot better today," Bradley said of Marks.

Wide receiver Marqise Lee was listed as out after not making the trip. He has missed the last three games with a hamstring issue.

The Jaguars, after traveling to London on Monday (2013) and Sunday evening (2014) for previous games at Wembley, opted to travel on Thursday evening/Friday morning this season. The idea was to give the game more of the feel of a regular road game.

Players were encouraged to sleep for as much of the seven-and-half-hour plane trip as possible, then the team went immediately into a meal and meetings upon arrival at the team hotel near Wembley. The team bused to practice about three hours after arriving at the hotel.

"We got them right off the bus, into the hotel, then right back into meetings," Bradley said. "It was a pretty active morning for them."

Bradley said he liked arriving late in the week.

"Our players had a good, sharp practice tonight and got some good rest," Bradley said, adding of the trip Thursday, "I walked around the plane. I think some had trouble sleeping, but for the most part they really took it (sleeping on the place) to heart."