ENGLEWOOD Royce Freeman Jersey , Colo. (AP) ¡ª cornerback Jamar Taylor and wide receiver Andre Holmes on board this week just to fill in at practice.¡°They¡¯re both dressing¡± Sunday at San Francisco, coach Vance Joseph said. ¡°You¡¯re going to see Andre out there playing (special) teams and playing on the offense. Jamar is going to be our fourth corner this week.¡±With cornerback Chris Harris Jr . (fractured fibula) and wide receiver Emmanuel Sanders (ruptured Achilles tendon) becoming the fifth and sixth opening-day starters to suffer major injuries, the Broncos become even more reliant on their strong rookie class ¡ª and the two newcomers who are scrambling to decipher Denver¡¯s playbook.It helps that both have a history of working with the Broncos¡¯ coaches.¡°I¡¯ve still got things to learn,¡± said Holmes, who is tapping into his time working with Broncos offensive coordinator Bill Musgrave in Oakland two years ago. ¡°There are some things I remember, but I¡¯m two years removed from his offense.¡±Taylor is a sixth-year pro who has played in 74 career games spanning stops in Miami ¡ª where Joseph was an assistant coach ¡ª Cleveland and Arizona. But this marks the first time he¡¯s switched teams midseason.¡°It¡¯s a little rough, you know, because you come in and you learn the playbook. You have to catch up right now,¡± Taylor said. ¡°Luckily, I have some of the same play-calling in Miami, so it¡¯s not too bad. But it¡¯s a lot of late nights.¡±The Broncos (6-6) have won three consecutive games for the first time under their second-year head coach, but the rash of injuries at key positions threatens to derail their playoff push.Losing longtime teammates Harris and Sanders in a 72-hour stretch hit fellow veterans hard.¡°I¡¯m still trying to get over the 88 trade,¡± Von Miller said of seeing Demaryius Thomas join the Houston Texans six week ago. ¡°Now we¡¯ve got 10 and 25. It¡¯s different. It¡¯s really different. But it¡¯s the pros. I hate to say it, but it¡¯s the pros and it¡¯s part of the game.¡±Now the Broncos have to lean even more on rookies Phillip Lindsay, Courtland Sutton, Bradley Chubb and Josey Jewell while carving out bigger roles for rookies Isaac Yiadom at cornerback and DaeSean Hamilton at wide receiver.¡°We¡¯re just inserting E. and the train moves on,¡± Joseph said Friday.With Hamilton starting along with Sutton, six rookies are slated to start for the Broncos on Sunday ¡ª seven, if you include their punter.¡°We have great confidence in our young class and they have confidence,¡± Joseph said. ¡°They¡¯re smart, they¡¯re tough and they¡¯ll play good football for us.¡±Joseph also trusts his newcomers will get up to speed quickly.¡°They¡¯re fine,¡± Joseph said. ¡°They¡¯re both pros. I had Jamar in Miami and Andre was with Billy for two years in Oakland. We¡¯re lucky to have those two guys that have played for us, that are healthy and are veteran players. We have no problem with those guys playing for us on Sunday.¡±PUNTER¡¯S PROGRESSColby Wadman is another rookie making his mark in Denver this season. He¡¯s received game balls in the last two weeks for his superb performances against Pittsburgh and Cincinnati.¡°Last week was special because of the wind John Elway Jersey ,¡± Joseph said. ¡°It was blowing out there and in that kind of game to help us flip the field multiple times, that was crucial in helping us win.¡±Special teams coach Tom McMahon discovered Wadman in 2017 while he was the Colts¡¯ special teams coordinator. On his way to work out Rigo Sanchez in Chico, California, he stopped by Davis, California, to work out Wadman.¡°I came back and I said, ¡®These two guys are dead even,'¡± McMahon said. ¡°We brought them both to minicamp and they finished minicamp dead even.¡±Wadman, however, doesn¡¯t kick off and with kicker Adam Vinatieri no longer handling kickoffs at age 45, the Colts punting job went to Sanchez.When Marquette King struggled early on in Denver this season, McMahon suggested the Broncos bring in Wadman because of his strong leg and good hang time, remembering that when he worked him out last year, ¡°it was one of those days where the wind was blowing all over the place and it didn¡¯t affect him at all.¡±Just like last week when the played the Bengals. The Broncos were short on cornerbacks at this week¡¯s voluntary minicamp.Chris Harris is absent while trying to land a new contract, Bryce Callahan is recovering from foot surgery and Isaac Yiadom is recovering from shoulder surgery, but practicing without those players didn¡¯t lead Denver to put free agent acquisition Kareem Jackson at cornerback for this week¡¯s workouts.Jackson worked at safety, which was something that head coach Vic Fangio suggested could be the case when Jackson signed with the team in March. Fangio said on Thursday that the decision to use Jackson there was because he¡¯s spent almost all of his career as a cornerback.¡°For the reason that there¡¯s more to learn at safety than there is at corner,¡± Fangio said, via KUSA. ¡°He¡¯s played much more corner in his career, so I wanted him to get more work in this camp ¡ª all of his work ¡ª at the safety position, to feel comfortable there.¡±Jackson¡¯s spot in the secondary once all hands are on deck will likely be more telling about the team¡¯s overall plans for how to make the best use of a new piece on their defense.